Merge "Correct a permission check / add a test" am: 05cf3e896c am: 04be13bb01 am: c58c250192

Change-Id: Iccd71c383788a21f12374d805cacbb3ff5b02771
diff --git a/services/core/java/com/android/server/timedetector/TimeDetectorService.java b/services/core/java/com/android/server/timedetector/TimeDetectorService.java
index b7d6360..0bb0f94 100644
--- a/services/core/java/com/android/server/timedetector/TimeDetectorService.java
+++ b/services/core/java/com/android/server/timedetector/TimeDetectorService.java
@@ -37,6 +37,9 @@
 import java.io.PrintWriter;
 import java.util.Objects;
 
+/**
+ * The implementation of ITimeDetectorService.aidl.
+ */
 public final class TimeDetectorService extends ITimeDetectorService.Stub {
     private static final String TAG = "TimeDetectorService";
 
@@ -75,7 +78,7 @@
                 Settings.Global.getUriFor(Settings.Global.AUTO_TIME), true,
                 new ContentObserver(handler) {
                     public void onChange(boolean selfChange) {
-                        timeDetectorService.handleAutoTimeDetectionToggle();
+                        timeDetectorService.handleAutoTimeDetectionChanged();
                     }
                 });
 
@@ -114,8 +117,9 @@
         mHandler.post(() -> mTimeDetectorStrategy.suggestNetworkTime(timeSignal));
     }
 
+    /** Internal method for handling the auto time setting being changed. */
     @VisibleForTesting
-    public void handleAutoTimeDetectionToggle() {
+    public void handleAutoTimeDetectionChanged() {
         mHandler.post(mTimeDetectorStrategy::handleAutoTimeDetectionChanged);
     }
 
diff --git a/services/core/java/com/android/server/timedetector/TimeDetectorStrategy.java b/services/core/java/com/android/server/timedetector/TimeDetectorStrategy.java
index 468b806..a7c3b4d 100644
--- a/services/core/java/com/android/server/timedetector/TimeDetectorStrategy.java
+++ b/services/core/java/com/android/server/timedetector/TimeDetectorStrategy.java
@@ -26,8 +26,8 @@
 import java.io.PrintWriter;
 
 /**
- * The interface for classes that implement the time detection algorithm used by the
- * TimeDetectorService.
+ * The interface for the class that implements the time detection algorithm used by the
+ * {@link TimeDetectorService}.
  *
  * <p>Most calls will be handled by a single thread but that is not true for all calls. For example
  * {@link #dump(PrintWriter, String[])}) may be called on a different thread so implementations must
diff --git a/services/core/java/com/android/server/timedetector/TimeDetectorStrategyImpl.java b/services/core/java/com/android/server/timedetector/TimeDetectorStrategyImpl.java
index a1e643f..19435ee 100644
--- a/services/core/java/com/android/server/timedetector/TimeDetectorStrategyImpl.java
+++ b/services/core/java/com/android/server/timedetector/TimeDetectorStrategyImpl.java
@@ -38,7 +38,7 @@
 import java.lang.annotation.RetentionPolicy;
 
 /**
- * An implementation of TimeDetectorStrategy that passes phone and manual suggestions to
+ * An implementation of {@link TimeDetectorStrategy} that passes phone and manual suggestions to
  * {@link AlarmManager}. When there are multiple phone sources, the one with the lowest ID is used
  * unless the data becomes too stale.
  *
diff --git a/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorCallbackImpl.java b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorCallbackImpl.java
index adf6d7e..2520316 100644
--- a/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorCallbackImpl.java
+++ b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorCallbackImpl.java
@@ -24,9 +24,9 @@
 import android.provider.Settings;
 
 /**
- * The real implementation of {@link TimeZoneDetectorStrategy.Callback}.
+ * The real implementation of {@link TimeZoneDetectorStrategyImpl.Callback}.
  */
-public final class TimeZoneDetectorCallbackImpl implements TimeZoneDetectorStrategy.Callback {
+public final class TimeZoneDetectorCallbackImpl implements TimeZoneDetectorStrategyImpl.Callback {
 
     private static final String TIMEZONE_PROPERTY = "persist.sys.timezone";
 
diff --git a/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorService.java b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorService.java
index 9a1fe65..381ee10 100644
--- a/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorService.java
+++ b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorService.java
@@ -67,19 +67,21 @@
 
     private static TimeZoneDetectorService create(@NonNull Context context) {
         final TimeZoneDetectorStrategy timeZoneDetectorStrategy =
-                TimeZoneDetectorStrategy.create(context);
+                TimeZoneDetectorStrategyImpl.create(context);
 
         Handler handler = FgThread.getHandler();
+        TimeZoneDetectorService service =
+                new TimeZoneDetectorService(context, handler, timeZoneDetectorStrategy);
+
         ContentResolver contentResolver = context.getContentResolver();
         contentResolver.registerContentObserver(
                 Settings.Global.getUriFor(Settings.Global.AUTO_TIME_ZONE), true,
                 new ContentObserver(handler) {
                     public void onChange(boolean selfChange) {
-                        timeZoneDetectorStrategy.handleAutoTimeZoneDetectionChange();
+                        service.handleAutoTimeZoneDetectionChanged();
                     }
                 });
-
-        return new TimeZoneDetectorService(context, handler, timeZoneDetectorStrategy);
+        return service;
     }
 
     @VisibleForTesting
@@ -111,17 +113,25 @@
             @Nullable String[] args) {
         if (!DumpUtils.checkDumpPermission(mContext, TAG, pw)) return;
 
-        mTimeZoneDetectorStrategy.dumpState(pw, args);
+        mTimeZoneDetectorStrategy.dump(pw, args);
+    }
+
+    /** Internal method for handling the auto time zone setting being changed. */
+    @VisibleForTesting
+    public void handleAutoTimeZoneDetectionChanged() {
+        mHandler.post(mTimeZoneDetectorStrategy::handleAutoTimeZoneDetectionChanged);
     }
 
     private void enforceSuggestPhoneTimeZonePermission() {
         mContext.enforceCallingPermission(
-                android.Manifest.permission.SET_TIME_ZONE, "set time zone");
+                android.Manifest.permission.SUGGEST_PHONE_TIME_AND_ZONE,
+                "suggest phone time and time zone");
     }
 
     private void enforceSuggestManualTimeZonePermission() {
         mContext.enforceCallingOrSelfPermission(
-                android.Manifest.permission.SET_TIME_ZONE, "set time zone");
+                android.Manifest.permission.SUGGEST_MANUAL_TIME_AND_ZONE,
+                "suggest manual time and time zone");
     }
 }
 
diff --git a/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorStrategy.java b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorStrategy.java
index b0e0069..1d439e9 100644
--- a/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorStrategy.java
+++ b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorStrategy.java
@@ -15,192 +15,26 @@
  */
 package com.android.server.timezonedetector;
 
-import static android.app.timezonedetector.PhoneTimeZoneSuggestion.MATCH_TYPE_EMULATOR_ZONE_ID;
-import static android.app.timezonedetector.PhoneTimeZoneSuggestion.MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY;
-import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS;
-import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET;
-import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_SINGLE_ZONE;
-
-import android.annotation.IntDef;
 import android.annotation.NonNull;
-import android.annotation.Nullable;
 import android.app.timezonedetector.ManualTimeZoneSuggestion;
 import android.app.timezonedetector.PhoneTimeZoneSuggestion;
-import android.content.Context;
-import android.util.LocalLog;
-import android.util.Slog;
-
-import com.android.internal.annotations.GuardedBy;
-import com.android.internal.annotations.VisibleForTesting;
-import com.android.internal.util.IndentingPrintWriter;
 
 import java.io.PrintWriter;
-import java.lang.annotation.Retention;
-import java.lang.annotation.RetentionPolicy;
-import java.util.Objects;
 
 /**
- * A singleton, stateful time zone detection strategy that is aware of user (manual) suggestions and
- * suggestions from multiple phone devices. Suggestions are acted on or ignored as needed, dependent
- * on the current "auto time zone detection" setting.
+ * The interface for the class that implement the time detection algorithm used by the
+ * {@link TimeZoneDetectorService}.
  *
- * <p>For automatic detection it keeps track of the most recent suggestion from each phone it uses
- * the best suggestion based on a scoring algorithm. If several phones provide the same score then
- * the phone with the lowest numeric ID "wins". If the situation changes and it is no longer
- * possible to be confident about the time zone, phones must submit an empty suggestion in order to
- * "withdraw" their previous suggestion.
+ * <p>Most calls will be handled by a single thread but that is not true for all calls. For example
+ * {@link #dump(PrintWriter, String[])}) may be called on a different thread so implementations must
+ * handle thread safety.
+ *
+ * @hide
  */
-public class TimeZoneDetectorStrategy {
+public interface TimeZoneDetectorStrategy {
 
-    /**
-     * Used by {@link TimeZoneDetectorStrategy} to interact with the surrounding service. It can be
-     * faked for tests.
-     *
-     * <p>Note: Because the system properties-derived values like
-     * {@link #isAutoTimeZoneDetectionEnabled()}, {@link #isAutoTimeZoneDetectionEnabled()},
-     * {@link #getDeviceTimeZone()} can be modified independently and from different threads (and
-     * processes!), their use are prone to race conditions. That will be true until the
-     * responsibility for setting their values is moved to {@link TimeZoneDetectorStrategy}.
-     */
-    @VisibleForTesting
-    public interface Callback {
-
-        /**
-         * Returns true if automatic time zone detection is enabled in settings.
-         */
-        boolean isAutoTimeZoneDetectionEnabled();
-
-        /**
-         * Returns true if the device has had an explicit time zone set.
-         */
-        boolean isDeviceTimeZoneInitialized();
-
-        /**
-         * Returns the device's currently configured time zone.
-         */
-        String getDeviceTimeZone();
-
-        /**
-         * Sets the device's time zone.
-         */
-        void setDeviceTimeZone(@NonNull String zoneId);
-    }
-
-    private static final String LOG_TAG = "TimeZoneDetectorStrategy";
-    private static final boolean DBG = false;
-
-    @IntDef({ ORIGIN_PHONE, ORIGIN_MANUAL })
-    @Retention(RetentionPolicy.SOURCE)
-    public @interface Origin {}
-
-    /** Used when a time value originated from a telephony signal. */
-    @Origin
-    private static final int ORIGIN_PHONE = 1;
-
-    /** Used when a time value originated from a user / manual settings. */
-    @Origin
-    private static final int ORIGIN_MANUAL = 2;
-
-    /**
-     * The abstract score for an empty or invalid phone suggestion.
-     *
-     * Used to score phone suggestions where there is no zone.
-     */
-    @VisibleForTesting
-    public static final int PHONE_SCORE_NONE = 0;
-
-    /**
-     * The abstract score for a low quality phone suggestion.
-     *
-     * Used to score suggestions where:
-     * The suggested zone ID is one of several possibilities, and the possibilities have different
-     * offsets.
-     *
-     * You would have to be quite desperate to want to use this choice.
-     */
-    @VisibleForTesting
-    public static final int PHONE_SCORE_LOW = 1;
-
-    /**
-     * The abstract score for a medium quality phone suggestion.
-     *
-     * Used for:
-     * The suggested zone ID is one of several possibilities but at least the possibilities have the
-     * same offset. Users would get the correct time but for the wrong reason. i.e. their device may
-     * switch to DST at the wrong time and (for example) their calendar events.
-     */
-    @VisibleForTesting
-    public static final int PHONE_SCORE_MEDIUM = 2;
-
-    /**
-     * The abstract score for a high quality phone suggestion.
-     *
-     * Used for:
-     * The suggestion was for one zone ID and the answer was unambiguous and likely correct given
-     * the info available.
-     */
-    @VisibleForTesting
-    public static final int PHONE_SCORE_HIGH = 3;
-
-    /**
-     * The abstract score for a highest quality phone suggestion.
-     *
-     * Used for:
-     * Suggestions that must "win" because they constitute test or emulator zone ID.
-     */
-    @VisibleForTesting
-    public static final int PHONE_SCORE_HIGHEST = 4;
-
-    /**
-     * The threshold at which phone suggestions are good enough to use to set the device's time
-     * zone.
-     */
-    @VisibleForTesting
-    public static final int PHONE_SCORE_USAGE_THRESHOLD = PHONE_SCORE_MEDIUM;
-
-    /** The number of previous phone suggestions to keep for each ID (for use during debugging). */
-    private static final int KEEP_PHONE_SUGGESTION_HISTORY_SIZE = 30;
-
-    @NonNull
-    private final Callback mCallback;
-
-    /**
-     * A log that records the decisions / decision metadata that affected the device's time zone
-     * (for use during debugging).
-     */
-    @NonNull
-    private final LocalLog mTimeZoneChangesLog = new LocalLog(30, false /* useLocalTimestamps */);
-
-    /**
-     * A mapping from slotIndex to a phone time zone suggestion. We typically expect one or two
-     * mappings: devices will have a small number of telephony devices and slotIndexs are assumed to
-     * be stable.
-     */
-    @GuardedBy("this")
-    private ArrayMapWithHistory<Integer, QualifiedPhoneTimeZoneSuggestion> mSuggestionBySlotIndex =
-            new ArrayMapWithHistory<>(KEEP_PHONE_SUGGESTION_HISTORY_SIZE);
-
-    /**
-     * Creates a new instance of {@link TimeZoneDetectorStrategy}.
-     */
-    public static TimeZoneDetectorStrategy create(Context context) {
-        Callback timeZoneDetectionServiceHelper = new TimeZoneDetectorCallbackImpl(context);
-        return new TimeZoneDetectorStrategy(timeZoneDetectionServiceHelper);
-    }
-
-    @VisibleForTesting
-    public TimeZoneDetectorStrategy(Callback callback) {
-        mCallback = Objects.requireNonNull(callback);
-    }
-
-    /** Process the suggested manually- / user-entered time zone. */
-    public synchronized void suggestManualTimeZone(@NonNull ManualTimeZoneSuggestion suggestion) {
-        Objects.requireNonNull(suggestion);
-
-        String timeZoneId = suggestion.getZoneId();
-        String cause = "Manual time suggestion received: suggestion=" + suggestion;
-        setDeviceTimeZoneIfRequired(ORIGIN_MANUAL, timeZoneId, cause);
-    }
+    /** Process the suggested manually-entered (i.e. user sourced) time zone. */
+    void suggestManualTimeZone(@NonNull ManualTimeZoneSuggestion suggestion);
 
     /**
      * Suggests a time zone for the device, or withdraws a previous suggestion if
@@ -210,312 +44,15 @@
      * suggestion. The strategy uses suggestions to decide whether to modify the device's time zone
      * setting and what to set it to.
      */
-    public synchronized void suggestPhoneTimeZone(@NonNull PhoneTimeZoneSuggestion suggestion) {
-        if (DBG) {
-            Slog.d(LOG_TAG, "Phone suggestion received. newSuggestion=" + suggestion);
-        }
-        Objects.requireNonNull(suggestion);
-
-        // Score the suggestion.
-        int score = scorePhoneSuggestion(suggestion);
-        QualifiedPhoneTimeZoneSuggestion scoredSuggestion =
-                new QualifiedPhoneTimeZoneSuggestion(suggestion, score);
-
-        // Store the suggestion against the correct slotIndex.
-        mSuggestionBySlotIndex.put(suggestion.getSlotIndex(), scoredSuggestion);
-
-        // Now perform auto time zone detection. The new suggestion may be used to modify the time
-        // zone setting.
-        String reason = "New phone time suggested. suggestion=" + suggestion;
-        doAutoTimeZoneDetection(reason);
-    }
-
-    private static int scorePhoneSuggestion(@NonNull PhoneTimeZoneSuggestion suggestion) {
-        int score;
-        if (suggestion.getZoneId() == null) {
-            score = PHONE_SCORE_NONE;
-        } else if (suggestion.getMatchType() == MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY
-                || suggestion.getMatchType() == MATCH_TYPE_EMULATOR_ZONE_ID) {
-            // Handle emulator / test cases : These suggestions should always just be used.
-            score = PHONE_SCORE_HIGHEST;
-        } else if (suggestion.getQuality() == QUALITY_SINGLE_ZONE) {
-            score = PHONE_SCORE_HIGH;
-        } else if (suggestion.getQuality() == QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET) {
-            // The suggestion may be wrong, but at least the offset should be correct.
-            score = PHONE_SCORE_MEDIUM;
-        } else if (suggestion.getQuality() == QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS) {
-            // The suggestion has a good chance of being wrong.
-            score = PHONE_SCORE_LOW;
-        } else {
-            throw new AssertionError();
-        }
-        return score;
-    }
-
-    /**
-     * Finds the best available time zone suggestion from all phones. If it is high-enough quality
-     * and automatic time zone detection is enabled then it will be set on the device. The outcome
-     * can be that this strategy becomes / remains un-opinionated and nothing is set.
-     */
-    @GuardedBy("this")
-    private void doAutoTimeZoneDetection(@NonNull String detectionReason) {
-        if (!mCallback.isAutoTimeZoneDetectionEnabled()) {
-            // Avoid doing unnecessary work with this (race-prone) check.
-            return;
-        }
-
-        QualifiedPhoneTimeZoneSuggestion bestPhoneSuggestion = findBestPhoneSuggestion();
-
-        // Work out what to do with the best suggestion.
-        if (bestPhoneSuggestion == null) {
-            // There is no phone suggestion available at all. Become un-opinionated.
-            if (DBG) {
-                Slog.d(LOG_TAG, "Could not determine time zone: No best phone suggestion."
-                        + " detectionReason=" + detectionReason);
-            }
-            return;
-        }
-
-        // Special case handling for uninitialized devices. This should only happen once.
-        String newZoneId = bestPhoneSuggestion.suggestion.getZoneId();
-        if (newZoneId != null && !mCallback.isDeviceTimeZoneInitialized()) {
-            String cause = "Device has no time zone set. Attempting to set the device to the best"
-                    + " available suggestion."
-                    + " bestPhoneSuggestion=" + bestPhoneSuggestion
-                    + ", detectionReason=" + detectionReason;
-            Slog.i(LOG_TAG, cause);
-            setDeviceTimeZoneIfRequired(ORIGIN_PHONE, newZoneId, cause);
-            return;
-        }
-
-        boolean suggestionGoodEnough = bestPhoneSuggestion.score >= PHONE_SCORE_USAGE_THRESHOLD;
-        if (!suggestionGoodEnough) {
-            if (DBG) {
-                Slog.d(LOG_TAG, "Best suggestion not good enough."
-                        + " bestPhoneSuggestion=" + bestPhoneSuggestion
-                        + ", detectionReason=" + detectionReason);
-            }
-            return;
-        }
-
-        // Paranoia: Every suggestion above the SCORE_USAGE_THRESHOLD should have a non-null time
-        // zone ID.
-        if (newZoneId == null) {
-            Slog.w(LOG_TAG, "Empty zone suggestion scored higher than expected. This is an error:"
-                    + " bestPhoneSuggestion=" + bestPhoneSuggestion
-                    + " detectionReason=" + detectionReason);
-            return;
-        }
-
-        String zoneId = bestPhoneSuggestion.suggestion.getZoneId();
-        String cause = "Found good suggestion."
-                + ", bestPhoneSuggestion=" + bestPhoneSuggestion
-                + ", detectionReason=" + detectionReason;
-        setDeviceTimeZoneIfRequired(ORIGIN_PHONE, zoneId, cause);
-    }
-
-    @GuardedBy("this")
-    private void setDeviceTimeZoneIfRequired(
-            @Origin int origin, @NonNull String newZoneId, @NonNull String cause) {
-        Objects.requireNonNull(newZoneId);
-        Objects.requireNonNull(cause);
-
-        boolean isOriginAutomatic = isOriginAutomatic(origin);
-        if (isOriginAutomatic) {
-            if (!mCallback.isAutoTimeZoneDetectionEnabled()) {
-                if (DBG) {
-                    Slog.d(LOG_TAG, "Auto time zone detection is not enabled."
-                            + " origin=" + origin
-                            + ", newZoneId=" + newZoneId
-                            + ", cause=" + cause);
-                }
-                return;
-            }
-        } else {
-            if (mCallback.isAutoTimeZoneDetectionEnabled()) {
-                if (DBG) {
-                    Slog.d(LOG_TAG, "Auto time zone detection is enabled."
-                            + " origin=" + origin
-                            + ", newZoneId=" + newZoneId
-                            + ", cause=" + cause);
-                }
-                return;
-            }
-        }
-
-        String currentZoneId = mCallback.getDeviceTimeZone();
-
-        // Avoid unnecessary changes / intents.
-        if (newZoneId.equals(currentZoneId)) {
-            // No need to set the device time zone - the setting is already what we would be
-            // suggesting.
-            if (DBG) {
-                Slog.d(LOG_TAG, "No need to change the time zone;"
-                        + " device is already set to the suggested zone."
-                        + " origin=" + origin
-                        + ", newZoneId=" + newZoneId
-                        + ", cause=" + cause);
-            }
-            return;
-        }
-
-        mCallback.setDeviceTimeZone(newZoneId);
-        String msg = "Set device time zone."
-                + " origin=" + origin
-                + ", currentZoneId=" + currentZoneId
-                + ", newZoneId=" + newZoneId
-                + ", cause=" + cause;
-        if (DBG) {
-            Slog.d(LOG_TAG, msg);
-        }
-        mTimeZoneChangesLog.log(msg);
-    }
-
-    private static boolean isOriginAutomatic(@Origin int origin) {
-        return origin != ORIGIN_MANUAL;
-    }
-
-    @GuardedBy("this")
-    @Nullable
-    private QualifiedPhoneTimeZoneSuggestion findBestPhoneSuggestion() {
-        QualifiedPhoneTimeZoneSuggestion bestSuggestion = null;
-
-        // Iterate over the latest QualifiedPhoneTimeZoneSuggestion objects received for each phone
-        // and find the best. Note that we deliberately do not look at age: the caller can
-        // rate-limit so age is not a strong indicator of confidence. Instead, the callers are
-        // expected to withdraw suggestions they no longer have confidence in.
-        for (int i = 0; i < mSuggestionBySlotIndex.size(); i++) {
-            QualifiedPhoneTimeZoneSuggestion candidateSuggestion =
-                    mSuggestionBySlotIndex.valueAt(i);
-            if (candidateSuggestion == null) {
-                // Unexpected
-                continue;
-            }
-
-            if (bestSuggestion == null) {
-                bestSuggestion = candidateSuggestion;
-            } else if (candidateSuggestion.score > bestSuggestion.score) {
-                bestSuggestion = candidateSuggestion;
-            } else if (candidateSuggestion.score == bestSuggestion.score) {
-                // Tie! Use the suggestion with the lowest slotIndex.
-                int candidateSlotIndex = candidateSuggestion.suggestion.getSlotIndex();
-                int bestSlotIndex = bestSuggestion.suggestion.getSlotIndex();
-                if (candidateSlotIndex < bestSlotIndex) {
-                    bestSuggestion = candidateSuggestion;
-                }
-            }
-        }
-        return bestSuggestion;
-    }
-
-    /**
-     * Returns the current best phone suggestion. Not intended for general use: it is used during
-     * tests to check strategy behavior.
-     */
-    @VisibleForTesting
-    @Nullable
-    public synchronized QualifiedPhoneTimeZoneSuggestion findBestPhoneSuggestionForTests() {
-        return findBestPhoneSuggestion();
-    }
+    void suggestPhoneTimeZone(@NonNull PhoneTimeZoneSuggestion suggestion);
 
     /**
      * Called when there has been a change to the automatic time zone detection setting.
      */
-    @VisibleForTesting
-    public synchronized void handleAutoTimeZoneDetectionChange() {
-        if (DBG) {
-            Slog.d(LOG_TAG, "handleTimeZoneDetectionChange() called");
-        }
-        if (mCallback.isAutoTimeZoneDetectionEnabled()) {
-            // When the user enabled time zone detection, run the time zone detection and change the
-            // device time zone if possible.
-            String reason = "Auto time zone detection setting enabled.";
-            doAutoTimeZoneDetection(reason);
-        }
-    }
+    void handleAutoTimeZoneDetectionChanged();
 
     /**
      * Dumps internal state such as field values.
      */
-    public synchronized void dumpState(PrintWriter pw, String[] args) {
-        IndentingPrintWriter ipw = new IndentingPrintWriter(pw, " ");
-        ipw.println("TimeZoneDetectorStrategy:");
-
-        ipw.increaseIndent(); // level 1
-        ipw.println("mCallback.isTimeZoneDetectionEnabled()="
-                + mCallback.isAutoTimeZoneDetectionEnabled());
-        ipw.println("mCallback.isDeviceTimeZoneInitialized()="
-                + mCallback.isDeviceTimeZoneInitialized());
-        ipw.println("mCallback.getDeviceTimeZone()="
-                + mCallback.getDeviceTimeZone());
-
-        ipw.println("Time zone change log:");
-        ipw.increaseIndent(); // level 2
-        mTimeZoneChangesLog.dump(ipw);
-        ipw.decreaseIndent(); // level 2
-
-        ipw.println("Phone suggestion history:");
-        ipw.increaseIndent(); // level 2
-        mSuggestionBySlotIndex.dump(ipw);
-        ipw.decreaseIndent(); // level 2
-        ipw.decreaseIndent(); // level 1
-        ipw.flush();
-    }
-
-    /**
-     * A method used to inspect strategy state during tests. Not intended for general use.
-     */
-    @VisibleForTesting
-    public synchronized QualifiedPhoneTimeZoneSuggestion getLatestPhoneSuggestion(int slotIndex) {
-        return mSuggestionBySlotIndex.get(slotIndex);
-    }
-
-    /**
-     * A {@link PhoneTimeZoneSuggestion} with additional qualifying metadata.
-     */
-    @VisibleForTesting
-    public static class QualifiedPhoneTimeZoneSuggestion {
-
-        @VisibleForTesting
-        public final PhoneTimeZoneSuggestion suggestion;
-
-        /**
-         * The score the suggestion has been given. This can be used to rank against other
-         * suggestions of the same type.
-         */
-        @VisibleForTesting
-        public final int score;
-
-        @VisibleForTesting
-        public QualifiedPhoneTimeZoneSuggestion(PhoneTimeZoneSuggestion suggestion, int score) {
-            this.suggestion = suggestion;
-            this.score = score;
-        }
-
-        @Override
-        public boolean equals(Object o) {
-            if (this == o) {
-                return true;
-            }
-            if (o == null || getClass() != o.getClass()) {
-                return false;
-            }
-            QualifiedPhoneTimeZoneSuggestion that = (QualifiedPhoneTimeZoneSuggestion) o;
-            return score == that.score
-                    && suggestion.equals(that.suggestion);
-        }
-
-        @Override
-        public int hashCode() {
-            return Objects.hash(score, suggestion);
-        }
-
-        @Override
-        public String toString() {
-            return "QualifiedPhoneTimeZoneSuggestion{"
-                    + "suggestion=" + suggestion
-                    + ", score=" + score
-                    + '}';
-        }
-    }
+    void dump(PrintWriter pw, String[] args);
 }
diff --git a/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorStrategyImpl.java b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorStrategyImpl.java
new file mode 100644
index 0000000..f85f9fe
--- /dev/null
+++ b/services/core/java/com/android/server/timezonedetector/TimeZoneDetectorStrategyImpl.java
@@ -0,0 +1,514 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.server.timezonedetector;
+
+import static android.app.timezonedetector.PhoneTimeZoneSuggestion.MATCH_TYPE_EMULATOR_ZONE_ID;
+import static android.app.timezonedetector.PhoneTimeZoneSuggestion.MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY;
+import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS;
+import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET;
+import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_SINGLE_ZONE;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.app.timezonedetector.ManualTimeZoneSuggestion;
+import android.app.timezonedetector.PhoneTimeZoneSuggestion;
+import android.content.Context;
+import android.util.LocalLog;
+import android.util.Slog;
+
+import com.android.internal.annotations.GuardedBy;
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.internal.util.IndentingPrintWriter;
+
+import java.io.PrintWriter;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.util.Objects;
+
+/**
+ * An implementation of {@link TimeZoneDetectorStrategy} that handle telephony and manual
+ * suggestions. Suggestions are acted on or ignored as needed, dependent on the current "auto time
+ * zone detection" setting.
+ *
+ * <p>For automatic detection it keeps track of the most recent suggestion from each phone it uses
+ * the best suggestion based on a scoring algorithm. If several phones provide the same score then
+ * the phone with the lowest numeric ID "wins". If the situation changes and it is no longer
+ * possible to be confident about the time zone, phones must submit an empty suggestion in order to
+ * "withdraw" their previous suggestion.
+ *
+ * <p>Most public methods are marked synchronized to ensure thread safety around internal state.
+ */
+public final class TimeZoneDetectorStrategyImpl implements TimeZoneDetectorStrategy {
+
+    /**
+     * Used by {@link TimeZoneDetectorStrategyImpl} to interact with the surrounding service. It can
+     * be faked for tests.
+     *
+     * <p>Note: Because the system properties-derived values like
+     * {@link #isAutoTimeZoneDetectionEnabled()}, {@link #isAutoTimeZoneDetectionEnabled()},
+     * {@link #getDeviceTimeZone()} can be modified independently and from different threads (and
+     * processes!), their use are prone to race conditions. That will be true until the
+     * responsibility for setting their values is moved to {@link TimeZoneDetectorStrategyImpl}.
+     */
+    @VisibleForTesting
+    public interface Callback {
+
+        /**
+         * Returns true if automatic time zone detection is enabled in settings.
+         */
+        boolean isAutoTimeZoneDetectionEnabled();
+
+        /**
+         * Returns true if the device has had an explicit time zone set.
+         */
+        boolean isDeviceTimeZoneInitialized();
+
+        /**
+         * Returns the device's currently configured time zone.
+         */
+        String getDeviceTimeZone();
+
+        /**
+         * Sets the device's time zone.
+         */
+        void setDeviceTimeZone(@NonNull String zoneId);
+    }
+
+    private static final String LOG_TAG = "TimeZoneDetectorStrategy";
+    private static final boolean DBG = false;
+
+    @IntDef({ ORIGIN_PHONE, ORIGIN_MANUAL })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface Origin {}
+
+    /** Used when a time value originated from a telephony signal. */
+    @Origin
+    private static final int ORIGIN_PHONE = 1;
+
+    /** Used when a time value originated from a user / manual settings. */
+    @Origin
+    private static final int ORIGIN_MANUAL = 2;
+
+    /**
+     * The abstract score for an empty or invalid phone suggestion.
+     *
+     * Used to score phone suggestions where there is no zone.
+     */
+    @VisibleForTesting
+    public static final int PHONE_SCORE_NONE = 0;
+
+    /**
+     * The abstract score for a low quality phone suggestion.
+     *
+     * Used to score suggestions where:
+     * The suggested zone ID is one of several possibilities, and the possibilities have different
+     * offsets.
+     *
+     * You would have to be quite desperate to want to use this choice.
+     */
+    @VisibleForTesting
+    public static final int PHONE_SCORE_LOW = 1;
+
+    /**
+     * The abstract score for a medium quality phone suggestion.
+     *
+     * Used for:
+     * The suggested zone ID is one of several possibilities but at least the possibilities have the
+     * same offset. Users would get the correct time but for the wrong reason. i.e. their device may
+     * switch to DST at the wrong time and (for example) their calendar events.
+     */
+    @VisibleForTesting
+    public static final int PHONE_SCORE_MEDIUM = 2;
+
+    /**
+     * The abstract score for a high quality phone suggestion.
+     *
+     * Used for:
+     * The suggestion was for one zone ID and the answer was unambiguous and likely correct given
+     * the info available.
+     */
+    @VisibleForTesting
+    public static final int PHONE_SCORE_HIGH = 3;
+
+    /**
+     * The abstract score for a highest quality phone suggestion.
+     *
+     * Used for:
+     * Suggestions that must "win" because they constitute test or emulator zone ID.
+     */
+    @VisibleForTesting
+    public static final int PHONE_SCORE_HIGHEST = 4;
+
+    /**
+     * The threshold at which phone suggestions are good enough to use to set the device's time
+     * zone.
+     */
+    @VisibleForTesting
+    public static final int PHONE_SCORE_USAGE_THRESHOLD = PHONE_SCORE_MEDIUM;
+
+    /** The number of previous phone suggestions to keep for each ID (for use during debugging). */
+    private static final int KEEP_PHONE_SUGGESTION_HISTORY_SIZE = 30;
+
+    @NonNull
+    private final Callback mCallback;
+
+    /**
+     * A log that records the decisions / decision metadata that affected the device's time zone
+     * (for use during debugging).
+     */
+    @NonNull
+    private final LocalLog mTimeZoneChangesLog = new LocalLog(30, false /* useLocalTimestamps */);
+
+    /**
+     * A mapping from slotIndex to a phone time zone suggestion. We typically expect one or two
+     * mappings: devices will have a small number of telephony devices and slotIndexs are assumed to
+     * be stable.
+     */
+    @GuardedBy("this")
+    private ArrayMapWithHistory<Integer, QualifiedPhoneTimeZoneSuggestion> mSuggestionBySlotIndex =
+            new ArrayMapWithHistory<>(KEEP_PHONE_SUGGESTION_HISTORY_SIZE);
+
+    /**
+     * Creates a new instance of {@link TimeZoneDetectorStrategyImpl}.
+     */
+    public static TimeZoneDetectorStrategyImpl create(Context context) {
+        Callback timeZoneDetectionServiceHelper = new TimeZoneDetectorCallbackImpl(context);
+        return new TimeZoneDetectorStrategyImpl(timeZoneDetectionServiceHelper);
+    }
+
+    @VisibleForTesting
+    public TimeZoneDetectorStrategyImpl(Callback callback) {
+        mCallback = Objects.requireNonNull(callback);
+    }
+
+    @Override
+    public synchronized void suggestManualTimeZone(@NonNull ManualTimeZoneSuggestion suggestion) {
+        Objects.requireNonNull(suggestion);
+
+        String timeZoneId = suggestion.getZoneId();
+        String cause = "Manual time suggestion received: suggestion=" + suggestion;
+        setDeviceTimeZoneIfRequired(ORIGIN_MANUAL, timeZoneId, cause);
+    }
+
+    @Override
+    public synchronized void suggestPhoneTimeZone(@NonNull PhoneTimeZoneSuggestion suggestion) {
+        if (DBG) {
+            Slog.d(LOG_TAG, "Phone suggestion received. newSuggestion=" + suggestion);
+        }
+        Objects.requireNonNull(suggestion);
+
+        // Score the suggestion.
+        int score = scorePhoneSuggestion(suggestion);
+        QualifiedPhoneTimeZoneSuggestion scoredSuggestion =
+                new QualifiedPhoneTimeZoneSuggestion(suggestion, score);
+
+        // Store the suggestion against the correct slotIndex.
+        mSuggestionBySlotIndex.put(suggestion.getSlotIndex(), scoredSuggestion);
+
+        // Now perform auto time zone detection. The new suggestion may be used to modify the time
+        // zone setting.
+        String reason = "New phone time suggested. suggestion=" + suggestion;
+        doAutoTimeZoneDetection(reason);
+    }
+
+    private static int scorePhoneSuggestion(@NonNull PhoneTimeZoneSuggestion suggestion) {
+        int score;
+        if (suggestion.getZoneId() == null) {
+            score = PHONE_SCORE_NONE;
+        } else if (suggestion.getMatchType() == MATCH_TYPE_TEST_NETWORK_OFFSET_ONLY
+                || suggestion.getMatchType() == MATCH_TYPE_EMULATOR_ZONE_ID) {
+            // Handle emulator / test cases : These suggestions should always just be used.
+            score = PHONE_SCORE_HIGHEST;
+        } else if (suggestion.getQuality() == QUALITY_SINGLE_ZONE) {
+            score = PHONE_SCORE_HIGH;
+        } else if (suggestion.getQuality() == QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET) {
+            // The suggestion may be wrong, but at least the offset should be correct.
+            score = PHONE_SCORE_MEDIUM;
+        } else if (suggestion.getQuality() == QUALITY_MULTIPLE_ZONES_WITH_DIFFERENT_OFFSETS) {
+            // The suggestion has a good chance of being wrong.
+            score = PHONE_SCORE_LOW;
+        } else {
+            throw new AssertionError();
+        }
+        return score;
+    }
+
+    /**
+     * Finds the best available time zone suggestion from all phones. If it is high-enough quality
+     * and automatic time zone detection is enabled then it will be set on the device. The outcome
+     * can be that this strategy becomes / remains un-opinionated and nothing is set.
+     */
+    @GuardedBy("this")
+    private void doAutoTimeZoneDetection(@NonNull String detectionReason) {
+        if (!mCallback.isAutoTimeZoneDetectionEnabled()) {
+            // Avoid doing unnecessary work with this (race-prone) check.
+            return;
+        }
+
+        QualifiedPhoneTimeZoneSuggestion bestPhoneSuggestion = findBestPhoneSuggestion();
+
+        // Work out what to do with the best suggestion.
+        if (bestPhoneSuggestion == null) {
+            // There is no phone suggestion available at all. Become un-opinionated.
+            if (DBG) {
+                Slog.d(LOG_TAG, "Could not determine time zone: No best phone suggestion."
+                        + " detectionReason=" + detectionReason);
+            }
+            return;
+        }
+
+        // Special case handling for uninitialized devices. This should only happen once.
+        String newZoneId = bestPhoneSuggestion.suggestion.getZoneId();
+        if (newZoneId != null && !mCallback.isDeviceTimeZoneInitialized()) {
+            String cause = "Device has no time zone set. Attempting to set the device to the best"
+                    + " available suggestion."
+                    + " bestPhoneSuggestion=" + bestPhoneSuggestion
+                    + ", detectionReason=" + detectionReason;
+            Slog.i(LOG_TAG, cause);
+            setDeviceTimeZoneIfRequired(ORIGIN_PHONE, newZoneId, cause);
+            return;
+        }
+
+        boolean suggestionGoodEnough = bestPhoneSuggestion.score >= PHONE_SCORE_USAGE_THRESHOLD;
+        if (!suggestionGoodEnough) {
+            if (DBG) {
+                Slog.d(LOG_TAG, "Best suggestion not good enough."
+                        + " bestPhoneSuggestion=" + bestPhoneSuggestion
+                        + ", detectionReason=" + detectionReason);
+            }
+            return;
+        }
+
+        // Paranoia: Every suggestion above the SCORE_USAGE_THRESHOLD should have a non-null time
+        // zone ID.
+        if (newZoneId == null) {
+            Slog.w(LOG_TAG, "Empty zone suggestion scored higher than expected. This is an error:"
+                    + " bestPhoneSuggestion=" + bestPhoneSuggestion
+                    + " detectionReason=" + detectionReason);
+            return;
+        }
+
+        String zoneId = bestPhoneSuggestion.suggestion.getZoneId();
+        String cause = "Found good suggestion."
+                + ", bestPhoneSuggestion=" + bestPhoneSuggestion
+                + ", detectionReason=" + detectionReason;
+        setDeviceTimeZoneIfRequired(ORIGIN_PHONE, zoneId, cause);
+    }
+
+    @GuardedBy("this")
+    private void setDeviceTimeZoneIfRequired(
+            @Origin int origin, @NonNull String newZoneId, @NonNull String cause) {
+        Objects.requireNonNull(newZoneId);
+        Objects.requireNonNull(cause);
+
+        boolean isOriginAutomatic = isOriginAutomatic(origin);
+        if (isOriginAutomatic) {
+            if (!mCallback.isAutoTimeZoneDetectionEnabled()) {
+                if (DBG) {
+                    Slog.d(LOG_TAG, "Auto time zone detection is not enabled."
+                            + " origin=" + origin
+                            + ", newZoneId=" + newZoneId
+                            + ", cause=" + cause);
+                }
+                return;
+            }
+        } else {
+            if (mCallback.isAutoTimeZoneDetectionEnabled()) {
+                if (DBG) {
+                    Slog.d(LOG_TAG, "Auto time zone detection is enabled."
+                            + " origin=" + origin
+                            + ", newZoneId=" + newZoneId
+                            + ", cause=" + cause);
+                }
+                return;
+            }
+        }
+
+        String currentZoneId = mCallback.getDeviceTimeZone();
+
+        // Avoid unnecessary changes / intents.
+        if (newZoneId.equals(currentZoneId)) {
+            // No need to set the device time zone - the setting is already what we would be
+            // suggesting.
+            if (DBG) {
+                Slog.d(LOG_TAG, "No need to change the time zone;"
+                        + " device is already set to the suggested zone."
+                        + " origin=" + origin
+                        + ", newZoneId=" + newZoneId
+                        + ", cause=" + cause);
+            }
+            return;
+        }
+
+        mCallback.setDeviceTimeZone(newZoneId);
+        String msg = "Set device time zone."
+                + " origin=" + origin
+                + ", currentZoneId=" + currentZoneId
+                + ", newZoneId=" + newZoneId
+                + ", cause=" + cause;
+        if (DBG) {
+            Slog.d(LOG_TAG, msg);
+        }
+        mTimeZoneChangesLog.log(msg);
+    }
+
+    private static boolean isOriginAutomatic(@Origin int origin) {
+        return origin != ORIGIN_MANUAL;
+    }
+
+    @GuardedBy("this")
+    @Nullable
+    private QualifiedPhoneTimeZoneSuggestion findBestPhoneSuggestion() {
+        QualifiedPhoneTimeZoneSuggestion bestSuggestion = null;
+
+        // Iterate over the latest QualifiedPhoneTimeZoneSuggestion objects received for each phone
+        // and find the best. Note that we deliberately do not look at age: the caller can
+        // rate-limit so age is not a strong indicator of confidence. Instead, the callers are
+        // expected to withdraw suggestions they no longer have confidence in.
+        for (int i = 0; i < mSuggestionBySlotIndex.size(); i++) {
+            QualifiedPhoneTimeZoneSuggestion candidateSuggestion =
+                    mSuggestionBySlotIndex.valueAt(i);
+            if (candidateSuggestion == null) {
+                // Unexpected
+                continue;
+            }
+
+            if (bestSuggestion == null) {
+                bestSuggestion = candidateSuggestion;
+            } else if (candidateSuggestion.score > bestSuggestion.score) {
+                bestSuggestion = candidateSuggestion;
+            } else if (candidateSuggestion.score == bestSuggestion.score) {
+                // Tie! Use the suggestion with the lowest slotIndex.
+                int candidateSlotIndex = candidateSuggestion.suggestion.getSlotIndex();
+                int bestSlotIndex = bestSuggestion.suggestion.getSlotIndex();
+                if (candidateSlotIndex < bestSlotIndex) {
+                    bestSuggestion = candidateSuggestion;
+                }
+            }
+        }
+        return bestSuggestion;
+    }
+
+    /**
+     * Returns the current best phone suggestion. Not intended for general use: it is used during
+     * tests to check strategy behavior.
+     */
+    @VisibleForTesting
+    @Nullable
+    public synchronized QualifiedPhoneTimeZoneSuggestion findBestPhoneSuggestionForTests() {
+        return findBestPhoneSuggestion();
+    }
+
+    @Override
+    public synchronized void handleAutoTimeZoneDetectionChanged() {
+        if (DBG) {
+            Slog.d(LOG_TAG, "handleTimeZoneDetectionChange() called");
+        }
+        if (mCallback.isAutoTimeZoneDetectionEnabled()) {
+            // When the user enabled time zone detection, run the time zone detection and change the
+            // device time zone if possible.
+            String reason = "Auto time zone detection setting enabled.";
+            doAutoTimeZoneDetection(reason);
+        }
+    }
+
+    /**
+     * Dumps internal state such as field values.
+     */
+    @Override
+    public synchronized void dump(PrintWriter pw, String[] args) {
+        IndentingPrintWriter ipw = new IndentingPrintWriter(pw, " ");
+        ipw.println("TimeZoneDetectorStrategy:");
+
+        ipw.increaseIndent(); // level 1
+        ipw.println("mCallback.isTimeZoneDetectionEnabled()="
+                + mCallback.isAutoTimeZoneDetectionEnabled());
+        ipw.println("mCallback.isDeviceTimeZoneInitialized()="
+                + mCallback.isDeviceTimeZoneInitialized());
+        ipw.println("mCallback.getDeviceTimeZone()="
+                + mCallback.getDeviceTimeZone());
+
+        ipw.println("Time zone change log:");
+        ipw.increaseIndent(); // level 2
+        mTimeZoneChangesLog.dump(ipw);
+        ipw.decreaseIndent(); // level 2
+
+        ipw.println("Phone suggestion history:");
+        ipw.increaseIndent(); // level 2
+        mSuggestionBySlotIndex.dump(ipw);
+        ipw.decreaseIndent(); // level 2
+        ipw.decreaseIndent(); // level 1
+        ipw.flush();
+    }
+
+    /**
+     * A method used to inspect strategy state during tests. Not intended for general use.
+     */
+    @VisibleForTesting
+    public synchronized QualifiedPhoneTimeZoneSuggestion getLatestPhoneSuggestion(int slotIndex) {
+        return mSuggestionBySlotIndex.get(slotIndex);
+    }
+
+    /**
+     * A {@link PhoneTimeZoneSuggestion} with additional qualifying metadata.
+     */
+    @VisibleForTesting
+    public static class QualifiedPhoneTimeZoneSuggestion {
+
+        @VisibleForTesting
+        public final PhoneTimeZoneSuggestion suggestion;
+
+        /**
+         * The score the suggestion has been given. This can be used to rank against other
+         * suggestions of the same type.
+         */
+        @VisibleForTesting
+        public final int score;
+
+        @VisibleForTesting
+        public QualifiedPhoneTimeZoneSuggestion(PhoneTimeZoneSuggestion suggestion, int score) {
+            this.suggestion = suggestion;
+            this.score = score;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) {
+                return true;
+            }
+            if (o == null || getClass() != o.getClass()) {
+                return false;
+            }
+            QualifiedPhoneTimeZoneSuggestion that = (QualifiedPhoneTimeZoneSuggestion) o;
+            return score == that.score
+                    && suggestion.equals(that.suggestion);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(score, suggestion);
+        }
+
+        @Override
+        public String toString() {
+            return "QualifiedPhoneTimeZoneSuggestion{"
+                    + "suggestion=" + suggestion
+                    + ", score=" + score
+                    + '}';
+        }
+    }
+}
diff --git a/services/tests/servicestests/src/com/android/server/timedetector/TimeDetectorServiceTest.java b/services/tests/servicestests/src/com/android/server/timedetector/TimeDetectorServiceTest.java
index ae53692..218f43c 100644
--- a/services/tests/servicestests/src/com/android/server/timedetector/TimeDetectorServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/timedetector/TimeDetectorServiceTest.java
@@ -33,14 +33,13 @@
 import android.app.timedetector.PhoneTimeSuggestion;
 import android.content.Context;
 import android.content.pm.PackageManager;
-import android.os.Handler;
 import android.os.HandlerThread;
-import android.os.Looper;
-import android.os.Message;
 import android.os.TimestampedValue;
 
 import androidx.test.runner.AndroidJUnit4;
 
+import com.android.server.timezonedetector.TestHandler;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -108,7 +107,7 @@
                 eq(android.Manifest.permission.SUGGEST_PHONE_TIME_AND_ZONE),
                 anyString());
 
-        mTestHandler.waitForEmptyQueue();
+        mTestHandler.waitForMessagesToBeProcessed();
         mStubbedTimeDetectorStrategy.verifySuggestPhoneTimeCalled(phoneTimeSuggestion);
     }
 
@@ -140,7 +139,7 @@
                 eq(android.Manifest.permission.SUGGEST_MANUAL_TIME_AND_ZONE),
                 anyString());
 
-        mTestHandler.waitForEmptyQueue();
+        mTestHandler.waitForMessagesToBeProcessed();
         mStubbedTimeDetectorStrategy.verifySuggestManualTimeCalled(manualTimeSuggestion);
     }
 
@@ -170,7 +169,7 @@
         verify(mMockContext).enforceCallingOrSelfPermission(
                 eq(android.Manifest.permission.SET_TIME), anyString());
 
-        mTestHandler.waitForEmptyQueue();
+        mTestHandler.waitForMessagesToBeProcessed();
         mStubbedTimeDetectorStrategy.verifySuggestNetworkTimeCalled(NetworkTimeSuggestion);
     }
 
@@ -187,21 +186,23 @@
 
     @Test
     public void testAutoTimeDetectionToggle() throws Exception {
-        mTimeDetectorService.handleAutoTimeDetectionToggle();
+        mTimeDetectorService.handleAutoTimeDetectionChanged();
         mTestHandler.assertTotalMessagesEnqueued(1);
-        mTestHandler.waitForEmptyQueue();
-        mStubbedTimeDetectorStrategy.verifyHandleAutoTimeDetectionToggleCalled();
+        mTestHandler.waitForMessagesToBeProcessed();
+        mStubbedTimeDetectorStrategy.verifyHandleAutoTimeDetectionChangedCalled();
 
-        mTimeDetectorService.handleAutoTimeDetectionToggle();
+        mStubbedTimeDetectorStrategy.resetCallTracking();
+
+        mTimeDetectorService.handleAutoTimeDetectionChanged();
         mTestHandler.assertTotalMessagesEnqueued(2);
-        mTestHandler.waitForEmptyQueue();
-        mStubbedTimeDetectorStrategy.verifyHandleAutoTimeDetectionToggleCalled();
+        mTestHandler.waitForMessagesToBeProcessed();
+        mStubbedTimeDetectorStrategy.verifyHandleAutoTimeDetectionChangedCalled();
     }
 
     private static PhoneTimeSuggestion createPhoneTimeSuggestion() {
-        int phoneId = 1234;
+        int slotIndex = 1234;
         TimestampedValue<Long> timeValue = new TimestampedValue<>(100L, 1_000_000L);
-        return new PhoneTimeSuggestion.Builder(phoneId)
+        return new PhoneTimeSuggestion.Builder(slotIndex)
                 .setUtcTime(timeValue)
                 .build();
     }
@@ -222,7 +223,7 @@
         private PhoneTimeSuggestion mLastPhoneSuggestion;
         private ManualTimeSuggestion mLastManualSuggestion;
         private NetworkTimeSuggestion mLastNetworkSuggestion;
-        private boolean mLastAutoTimeDetectionToggleCalled;
+        private boolean mHandleAutoTimeDetectionChangedCalled;
         private boolean mDumpCalled;
 
         @Override
@@ -231,31 +232,26 @@
 
         @Override
         public void suggestPhoneTime(PhoneTimeSuggestion timeSuggestion) {
-            resetCallTracking();
             mLastPhoneSuggestion = timeSuggestion;
         }
 
         @Override
         public void suggestManualTime(ManualTimeSuggestion timeSuggestion) {
-            resetCallTracking();
             mLastManualSuggestion = timeSuggestion;
         }
 
         @Override
         public void suggestNetworkTime(NetworkTimeSuggestion timeSuggestion) {
-            resetCallTracking();
             mLastNetworkSuggestion = timeSuggestion;
         }
 
         @Override
         public void handleAutoTimeDetectionChanged() {
-            resetCallTracking();
-            mLastAutoTimeDetectionToggleCalled = true;
+            mHandleAutoTimeDetectionChangedCalled = true;
         }
 
         @Override
         public void dump(PrintWriter pw, String[] args) {
-            resetCallTracking();
             mDumpCalled = true;
         }
 
@@ -263,7 +259,7 @@
             mLastPhoneSuggestion = null;
             mLastManualSuggestion = null;
             mLastNetworkSuggestion = null;
-            mLastAutoTimeDetectionToggleCalled = false;
+            mHandleAutoTimeDetectionChangedCalled = false;
             mDumpCalled = false;
         }
 
@@ -279,45 +275,12 @@
             assertEquals(expectedSuggestion, mLastNetworkSuggestion);
         }
 
-        void verifyHandleAutoTimeDetectionToggleCalled() {
-            assertTrue(mLastAutoTimeDetectionToggleCalled);
+        void verifyHandleAutoTimeDetectionChangedCalled() {
+            assertTrue(mHandleAutoTimeDetectionChangedCalled);
         }
 
         void verifyDumpCalled() {
             assertTrue(mDumpCalled);
         }
     }
-
-    /**
-     * A Handler that can track posts/sends and wait for work to be completed.
-     */
-    private static class TestHandler extends Handler {
-
-        private int mMessagesSent;
-
-        TestHandler(Looper looper) {
-            super(looper);
-        }
-
-        @Override
-        public boolean sendMessageAtTime(Message msg, long uptimeMillis) {
-            mMessagesSent++;
-            return super.sendMessageAtTime(msg, uptimeMillis);
-        }
-
-        /** Asserts the number of messages posted or sent is as expected. */
-        void assertTotalMessagesEnqueued(int expected) {
-            assertEquals(expected, mMessagesSent);
-        }
-
-        /**
-         * Waits for all currently enqueued work due to be processed to be completed before
-         * returning.
-         */
-        void waitForEmptyQueue() throws InterruptedException {
-            while (!getLooper().getQueue().isIdle()) {
-                Thread.sleep(100);
-            }
-        }
-    }
 }
diff --git a/services/tests/servicestests/src/com/android/server/timezonedetector/TestHandler.java b/services/tests/servicestests/src/com/android/server/timezonedetector/TestHandler.java
new file mode 100644
index 0000000..21c9685
--- /dev/null
+++ b/services/tests/servicestests/src/com/android/server/timezonedetector/TestHandler.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.server.timezonedetector;
+
+import static org.junit.Assert.assertEquals;
+
+import android.os.Handler;
+import android.os.Looper;
+import android.os.Message;
+
+/**
+ * A Handler that can track posts/sends and wait for them to be completed.
+ */
+public class TestHandler extends Handler {
+
+    private final Object mMonitor = new Object();
+    private int mMessagesProcessed = 0;
+    private int mMessagesSent = 0;
+
+    public TestHandler(Looper looper) {
+        super(looper);
+    }
+
+    @Override
+    public boolean sendMessageAtTime(Message msg, long uptimeMillis) {
+        synchronized (mMonitor) {
+            mMessagesSent++;
+        }
+
+        Runnable callback = msg.getCallback();
+        // Have the callback increment the mMessagesProcessed when it is done. It will notify
+        // any threads waiting for all messages to be processed if appropriate.
+        Runnable newCallback = () -> {
+            callback.run();
+            synchronized (mMonitor) {
+                mMessagesProcessed++;
+                if (mMessagesSent == mMessagesProcessed) {
+                    mMonitor.notifyAll();
+                }
+            }
+        };
+        msg.setCallback(newCallback);
+        return super.sendMessageAtTime(msg, uptimeMillis);
+    }
+
+    /** Asserts the number of messages posted or sent is as expected. */
+    public void assertTotalMessagesEnqueued(int expected) {
+        synchronized (mMonitor) {
+            assertEquals(expected, mMessagesSent);
+        }
+    }
+
+    /**
+     * Waits for all enqueued work to be completed before returning.
+     */
+    public void waitForMessagesToBeProcessed() throws InterruptedException {
+        synchronized (mMonitor) {
+            if (mMessagesSent != mMessagesProcessed) {
+                mMonitor.wait();
+            }
+        }
+    }
+}
diff --git a/services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorServiceTest.java b/services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorServiceTest.java
new file mode 100644
index 0000000..3e7d40a
--- /dev/null
+++ b/services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorServiceTest.java
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.timezonedetector;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.app.timezonedetector.ManualTimeZoneSuggestion;
+import android.app.timezonedetector.PhoneTimeZoneSuggestion;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.os.HandlerThread;
+
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.io.PrintWriter;
+
+@RunWith(AndroidJUnit4.class)
+public class TimeZoneDetectorServiceTest {
+
+    private Context mMockContext;
+    private StubbedTimeZoneDetectorStrategy mStubbedTimeZoneDetectorStrategy;
+
+    private TimeZoneDetectorService mTimeZoneDetectorService;
+    private HandlerThread mHandlerThread;
+    private TestHandler mTestHandler;
+
+
+    @Before
+    public void setUp() {
+        mMockContext = mock(Context.class);
+
+        // Create a thread + handler for processing the work that the service posts.
+        mHandlerThread = new HandlerThread("TimeZoneDetectorServiceTest");
+        mHandlerThread.start();
+        mTestHandler = new TestHandler(mHandlerThread.getLooper());
+
+        mStubbedTimeZoneDetectorStrategy = new StubbedTimeZoneDetectorStrategy();
+
+        mTimeZoneDetectorService = new TimeZoneDetectorService(
+                mMockContext, mTestHandler, mStubbedTimeZoneDetectorStrategy);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        mHandlerThread.quit();
+        mHandlerThread.join();
+    }
+
+    @Test(expected = SecurityException.class)
+    public void testSuggestPhoneTime_withoutPermission() {
+        doThrow(new SecurityException("Mock"))
+                .when(mMockContext).enforceCallingPermission(anyString(), any());
+        PhoneTimeZoneSuggestion timeZoneSuggestion = createPhoneTimeZoneSuggestion();
+
+        try {
+            mTimeZoneDetectorService.suggestPhoneTimeZone(timeZoneSuggestion);
+            fail();
+        } finally {
+            verify(mMockContext).enforceCallingPermission(
+                    eq(android.Manifest.permission.SUGGEST_PHONE_TIME_AND_ZONE),
+                    anyString());
+        }
+    }
+
+    @Test
+    public void testSuggestPhoneTimeZone() throws Exception {
+        doNothing().when(mMockContext).enforceCallingPermission(anyString(), any());
+
+        PhoneTimeZoneSuggestion timeZoneSuggestion = createPhoneTimeZoneSuggestion();
+        mTimeZoneDetectorService.suggestPhoneTimeZone(timeZoneSuggestion);
+        mTestHandler.assertTotalMessagesEnqueued(1);
+
+        verify(mMockContext).enforceCallingPermission(
+                eq(android.Manifest.permission.SUGGEST_PHONE_TIME_AND_ZONE),
+                anyString());
+
+        mTestHandler.waitForMessagesToBeProcessed();
+        mStubbedTimeZoneDetectorStrategy.verifySuggestPhoneTimeZoneCalled(timeZoneSuggestion);
+    }
+
+    @Test(expected = SecurityException.class)
+    public void testSuggestManualTime_withoutPermission() {
+        doThrow(new SecurityException("Mock"))
+                .when(mMockContext).enforceCallingOrSelfPermission(anyString(), any());
+        ManualTimeZoneSuggestion timeZoneSuggestion = createManualTimeZoneSuggestion();
+
+        try {
+            mTimeZoneDetectorService.suggestManualTimeZone(timeZoneSuggestion);
+            fail();
+        } finally {
+            verify(mMockContext).enforceCallingOrSelfPermission(
+                    eq(android.Manifest.permission.SUGGEST_MANUAL_TIME_AND_ZONE),
+                    anyString());
+        }
+    }
+
+    @Test
+    public void testSuggestManualTimeZone() throws Exception {
+        doNothing().when(mMockContext).enforceCallingOrSelfPermission(anyString(), any());
+
+        ManualTimeZoneSuggestion timeZoneSuggestion = createManualTimeZoneSuggestion();
+        mTimeZoneDetectorService.suggestManualTimeZone(timeZoneSuggestion);
+        mTestHandler.assertTotalMessagesEnqueued(1);
+
+        verify(mMockContext).enforceCallingOrSelfPermission(
+                eq(android.Manifest.permission.SUGGEST_MANUAL_TIME_AND_ZONE),
+                anyString());
+
+        mTestHandler.waitForMessagesToBeProcessed();
+        mStubbedTimeZoneDetectorStrategy.verifySuggestManualTimeZoneCalled(timeZoneSuggestion);
+    }
+
+    @Test
+    public void testDump() {
+        when(mMockContext.checkCallingOrSelfPermission(android.Manifest.permission.DUMP))
+                .thenReturn(PackageManager.PERMISSION_GRANTED);
+
+        mTimeZoneDetectorService.dump(null, null, null);
+
+        verify(mMockContext).checkCallingOrSelfPermission(eq(android.Manifest.permission.DUMP));
+        mStubbedTimeZoneDetectorStrategy.verifyDumpCalled();
+    }
+
+    @Test
+    public void testAutoTimeZoneDetectionChanged() throws Exception {
+        mTimeZoneDetectorService.handleAutoTimeZoneDetectionChanged();
+        mTestHandler.assertTotalMessagesEnqueued(1);
+        mTestHandler.waitForMessagesToBeProcessed();
+        mStubbedTimeZoneDetectorStrategy.verifyHandleAutoTimeZoneDetectionChangedCalled();
+
+        mStubbedTimeZoneDetectorStrategy.resetCallTracking();
+
+        mTimeZoneDetectorService.handleAutoTimeZoneDetectionChanged();
+        mTestHandler.assertTotalMessagesEnqueued(2);
+        mTestHandler.waitForMessagesToBeProcessed();
+        mStubbedTimeZoneDetectorStrategy.verifyHandleAutoTimeZoneDetectionChangedCalled();
+    }
+
+    private static PhoneTimeZoneSuggestion createPhoneTimeZoneSuggestion() {
+        int slotIndex = 1234;
+        return new PhoneTimeZoneSuggestion.Builder(slotIndex)
+                .setZoneId("TestZoneId")
+                .setMatchType(PhoneTimeZoneSuggestion.MATCH_TYPE_NETWORK_COUNTRY_AND_OFFSET)
+                .setQuality(PhoneTimeZoneSuggestion.QUALITY_SINGLE_ZONE)
+                .build();
+    }
+
+    private static ManualTimeZoneSuggestion createManualTimeZoneSuggestion() {
+        return new ManualTimeZoneSuggestion("TestZoneId");
+    }
+
+    private static class StubbedTimeZoneDetectorStrategy implements TimeZoneDetectorStrategy {
+
+        // Call tracking.
+        private PhoneTimeZoneSuggestion mLastPhoneSuggestion;
+        private ManualTimeZoneSuggestion mLastManualSuggestion;
+        private boolean mHandleAutoTimeZoneDetectionChangedCalled;
+        private boolean mDumpCalled;
+
+        @Override
+        public void suggestPhoneTimeZone(PhoneTimeZoneSuggestion timeZoneSuggestion) {
+            mLastPhoneSuggestion = timeZoneSuggestion;
+        }
+
+        @Override
+        public void suggestManualTimeZone(ManualTimeZoneSuggestion timeZoneSuggestion) {
+            mLastManualSuggestion = timeZoneSuggestion;
+        }
+
+        @Override
+        public void handleAutoTimeZoneDetectionChanged() {
+            mHandleAutoTimeZoneDetectionChangedCalled = true;
+        }
+
+        @Override
+        public void dump(PrintWriter pw, String[] args) {
+            mDumpCalled = true;
+        }
+
+        void resetCallTracking() {
+            mLastPhoneSuggestion = null;
+            mLastManualSuggestion = null;
+            mHandleAutoTimeZoneDetectionChangedCalled = false;
+            mDumpCalled = false;
+        }
+
+        void verifySuggestPhoneTimeZoneCalled(PhoneTimeZoneSuggestion expectedSuggestion) {
+            assertEquals(expectedSuggestion, mLastPhoneSuggestion);
+        }
+
+        public void verifySuggestManualTimeZoneCalled(ManualTimeZoneSuggestion expectedSuggestion) {
+            assertEquals(expectedSuggestion, mLastManualSuggestion);
+        }
+
+        void verifyHandleAutoTimeZoneDetectionChangedCalled() {
+            assertTrue(mHandleAutoTimeZoneDetectionChangedCalled);
+        }
+
+        void verifyDumpCalled() {
+            assertTrue(mDumpCalled);
+        }
+    }
+
+}
diff --git a/services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorStrategyTest.java b/services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorStrategyImplTest.java
similarity index 96%
rename from services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorStrategyTest.java
rename to services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorStrategyImplTest.java
index 2429cfc..1e38711 100644
--- a/services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorStrategyTest.java
+++ b/services/tests/servicestests/src/com/android/server/timezonedetector/TimeZoneDetectorStrategyImplTest.java
@@ -24,12 +24,12 @@
 import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_MULTIPLE_ZONES_WITH_SAME_OFFSET;
 import static android.app.timezonedetector.PhoneTimeZoneSuggestion.QUALITY_SINGLE_ZONE;
 
-import static com.android.server.timezonedetector.TimeZoneDetectorStrategy.PHONE_SCORE_HIGH;
-import static com.android.server.timezonedetector.TimeZoneDetectorStrategy.PHONE_SCORE_HIGHEST;
-import static com.android.server.timezonedetector.TimeZoneDetectorStrategy.PHONE_SCORE_LOW;
-import static com.android.server.timezonedetector.TimeZoneDetectorStrategy.PHONE_SCORE_MEDIUM;
-import static com.android.server.timezonedetector.TimeZoneDetectorStrategy.PHONE_SCORE_NONE;
-import static com.android.server.timezonedetector.TimeZoneDetectorStrategy.PHONE_SCORE_USAGE_THRESHOLD;
+import static com.android.server.timezonedetector.TimeZoneDetectorStrategyImpl.PHONE_SCORE_HIGH;
+import static com.android.server.timezonedetector.TimeZoneDetectorStrategyImpl.PHONE_SCORE_HIGHEST;
+import static com.android.server.timezonedetector.TimeZoneDetectorStrategyImpl.PHONE_SCORE_LOW;
+import static com.android.server.timezonedetector.TimeZoneDetectorStrategyImpl.PHONE_SCORE_MEDIUM;
+import static com.android.server.timezonedetector.TimeZoneDetectorStrategyImpl.PHONE_SCORE_NONE;
+import static com.android.server.timezonedetector.TimeZoneDetectorStrategyImpl.PHONE_SCORE_USAGE_THRESHOLD;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -41,7 +41,7 @@
 import android.app.timezonedetector.PhoneTimeZoneSuggestion.MatchType;
 import android.app.timezonedetector.PhoneTimeZoneSuggestion.Quality;
 
-import com.android.server.timezonedetector.TimeZoneDetectorStrategy.QualifiedPhoneTimeZoneSuggestion;
+import com.android.server.timezonedetector.TimeZoneDetectorStrategyImpl.QualifiedPhoneTimeZoneSuggestion;
 
 import org.junit.Before;
 import org.junit.Test;
@@ -52,9 +52,9 @@
 import java.util.LinkedList;
 
 /**
- * White-box unit tests for {@link TimeZoneDetectorStrategy}.
+ * White-box unit tests for {@link TimeZoneDetectorStrategyImpl}.
  */
-public class TimeZoneDetectorStrategyTest {
+public class TimeZoneDetectorStrategyImplTest {
 
     /** A time zone used for initialization that does not occur elsewhere in tests. */
     private static final String ARBITRARY_TIME_ZONE_ID = "Etc/UTC";
@@ -78,14 +78,14 @@
             newTestCase(MATCH_TYPE_EMULATOR_ZONE_ID, QUALITY_SINGLE_ZONE, PHONE_SCORE_HIGHEST),
     };
 
-    private TimeZoneDetectorStrategy mTimeZoneDetectorStrategy;
+    private TimeZoneDetectorStrategyImpl mTimeZoneDetectorStrategy;
     private FakeTimeZoneDetectorStrategyCallback mFakeTimeZoneDetectorStrategyCallback;
 
     @Before
     public void setUp() {
         mFakeTimeZoneDetectorStrategyCallback = new FakeTimeZoneDetectorStrategyCallback();
         mTimeZoneDetectorStrategy =
-                new TimeZoneDetectorStrategy(mFakeTimeZoneDetectorStrategyCallback);
+                new TimeZoneDetectorStrategyImpl(mFakeTimeZoneDetectorStrategyCallback);
     }
 
     @Test
@@ -364,7 +364,7 @@
     }
 
     /**
-     * The {@link TimeZoneDetectorStrategy.Callback} is left to detect whether changing the time
+     * The {@link TimeZoneDetectorStrategyImpl.Callback} is left to detect whether changing the time
      * zone is actually necessary. This test proves that the service doesn't assume it knows the
      * current setting.
      */
@@ -441,7 +441,8 @@
         return new PhoneTimeZoneSuggestion.Builder(PHONE2_ID).build();
     }
 
-    static class FakeTimeZoneDetectorStrategyCallback implements TimeZoneDetectorStrategy.Callback {
+    static class FakeTimeZoneDetectorStrategyCallback
+            implements TimeZoneDetectorStrategyImpl.Callback {
 
         private boolean mAutoTimeZoneDetectionEnabled;
         private TestState<String> mTimeZoneId = new TestState<>();
@@ -560,7 +561,7 @@
 
         Script autoTimeZoneDetectionEnabled(boolean enabled) {
             mFakeTimeZoneDetectorStrategyCallback.setAutoTimeZoneDetectionEnabled(enabled);
-            mTimeZoneDetectorStrategy.handleAutoTimeZoneDetectionChange();
+            mTimeZoneDetectorStrategy.handleAutoTimeZoneDetectionChanged();
             return this;
         }