diff --git a/core/java/android/widget/Editor.java b/core/java/android/widget/Editor.java
index bb9bd52..c821774 100644
--- a/core/java/android/widget/Editor.java
+++ b/core/java/android/widget/Editor.java
@@ -3531,8 +3531,8 @@
         }
     }
 
-    @VisibleForTesting
-    public class SuggestionsPopupWindow extends PinnedPopupWindow implements OnItemClickListener {
+    private final class SuggestionsPopupWindow extends PinnedPopupWindow
+            implements OnItemClickListener {
         private static final int MAX_NUMBER_SUGGESTIONS = SuggestionSpan.SUGGESTIONS_MAX_SIZE;
 
         // Key of intent extras for inserting new word into user dictionary.
@@ -3734,11 +3734,6 @@
             }
         }
 
-        @VisibleForTesting
-        public ViewGroup getContentViewForTesting() {
-            return mContentView;
-        }
-
         @Override
         public void show() {
             if (!(mTextView.getText() instanceof Editable)) return;
@@ -6460,11 +6455,6 @@
         return 0 <= start && start <= end && end <= text.length();
     }
 
-    @VisibleForTesting
-    public SuggestionsPopupWindow getSuggestionsPopupWindowForTesting() {
-        return mSuggestionsPopupWindow;
-    }
-
     /**
      * An InputFilter that monitors text input to maintain undo history. It does not modify the
      * text being typed (and hence always returns null from the filter() method).
diff --git a/core/jni/android_util_Process.cpp b/core/jni/android_util_Process.cpp
index 26a474c..2d7069c 100644
--- a/core/jni/android_util_Process.cpp
+++ b/core/jni/android_util_Process.cpp
@@ -355,30 +355,34 @@
 static void get_cpuset_cores_for_policy(SchedPolicy policy, cpu_set_t *cpu_set)
 {
     FILE *file;
-    const char *filename;
+    std::string filename;
 
     CPU_ZERO(cpu_set);
 
     switch (policy) {
         case SP_BACKGROUND:
-            filename = "/dev/cpuset/background/cpus";
+            if (!CgroupGetAttributePath("LowCapacityCPUs", &filename)) {
+                return;
+            }
             break;
         case SP_FOREGROUND:
         case SP_AUDIO_APP:
         case SP_AUDIO_SYS:
         case SP_RT_APP:
-            filename = "/dev/cpuset/foreground/cpus";
+            if (!CgroupGetAttributePath("HighCapacityCPUs", &filename)) {
+                return;
+            }
             break;
         case SP_TOP_APP:
-            filename = "/dev/cpuset/top-app/cpus";
+            if (!CgroupGetAttributePath("MaxCapacityCPUs", &filename)) {
+                return;
+            }
             break;
         default:
-            filename = NULL;
+            return;
     }
 
-    if (!filename) return;
-
-    file = fopen(filename, "re");
+    file = fopen(filename.c_str(), "re");
     if (file != NULL) {
         // Parse cpus string
         char *line = NULL;
@@ -388,7 +392,7 @@
         if (num_read > 0) {
             parse_cpuset_cpus(line, cpu_set);
         } else {
-            ALOGE("Failed to read %s", filename);
+            ALOGE("Failed to read %s", filename.c_str());
         }
         free(line);
     }
diff --git a/core/jni/com_android_internal_os_Zygote.cpp b/core/jni/com_android_internal_os_Zygote.cpp
index b7837ef..5a65028 100644
--- a/core/jni/com_android_internal_os_Zygote.cpp
+++ b/core/jni/com_android_internal_os_Zygote.cpp
@@ -1534,15 +1534,12 @@
           RuntimeAbort(env, __LINE__, "System server process has died. Restarting Zygote!");
       }
 
-      bool low_ram_device = GetBoolProperty("ro.config.low_ram", false);
-      bool per_app_memcg = GetBoolProperty("ro.config.per_app_memcg", low_ram_device);
-      if (per_app_memcg) {
+      if (UsePerAppMemcg()) {
           // Assign system_server to the correct memory cgroup.
-          // Not all devices mount /dev/memcg so check for the file first
+          // Not all devices mount memcg so check if it is mounted first
           // to avoid unnecessarily printing errors and denials in the logs.
-          if (!access("/dev/memcg/system/tasks", F_OK) &&
-                !WriteStringToFile(StringPrintf("%d", pid), "/dev/memcg/system/tasks")) {
-              ALOGE("couldn't write %d to /dev/memcg/system/tasks", pid);
+          if (!SetTaskProfiles(pid, std::vector<std::string>{"SystemMemoryProcess"})) {
+              ALOGE("couldn't add process %d into system memcg group", pid);
           }
       }
   }
diff --git a/core/res/res/values/colors_car.xml b/core/res/res/values/colors_car.xml
index f4aeff7..82caa26 100644
--- a/core/res/res/values/colors_car.xml
+++ b/core/res/res/values/colors_car.xml
@@ -137,8 +137,8 @@
     <color name="car_toast_background">#E6282a2d</color>
 
     <!-- Misc colors -->
-    <color name="car_highlight_light">@color/car_teal_200</color>
-    <color name="car_highlight_dark">@color/car_teal_200</color>
+    <color name="car_highlight_light">#ff66b5ff</color>
+    <color name="car_highlight_dark">#ff60a8f0</color>
     <color name="car_highlight">@color/car_highlight_dark</color>
     <color name="car_accent_light">@color/car_highlight_light</color>
     <color name="car_accent_dark">@color/car_highlight_dark</color>
diff --git a/media/jni/Android.bp b/media/jni/Android.bp
index f1bb13d..8ed265d 100644
--- a/media/jni/Android.bp
+++ b/media/jni/Android.bp
@@ -48,6 +48,7 @@
         "libmtp",
         "libexif",
         "libpiex",
+        "libprocessgroup",
         "libandroidfw",
         "libhidlallocatorutils",
         "libhidlbase",
@@ -123,6 +124,7 @@
         "libbase",
         "libcrypto",
         "libcutils",
+        "libjsoncpp",
         "libmedia_helper",
         "libmedia_player2_util",
         "libmediaplayer2",
diff --git a/services/core/java/com/android/server/wm/ActivityDisplay.java b/services/core/java/com/android/server/wm/ActivityDisplay.java
index e817dd4..5b3a2fe 100644
--- a/services/core/java/com/android/server/wm/ActivityDisplay.java
+++ b/services/core/java/com/android/server/wm/ActivityDisplay.java
@@ -1267,6 +1267,15 @@
         positionChildAt(stack, Math.max(0, insertIndex));
     }
 
+    void ensureActivitiesVisible(ActivityRecord starting, int configChanges,
+            boolean preserveWindows, boolean notifyClients) {
+        for (int stackNdx = getChildCount() - 1; stackNdx >= 0; --stackNdx) {
+            final ActivityStack stack = getChildAt(stackNdx);
+            stack.ensureActivitiesVisibleLocked(starting, configChanges, preserveWindows,
+                    notifyClients);
+        }
+    }
+
     void moveHomeStackToFront(String reason) {
         if (mHomeStack != null) {
             mHomeStack.moveToFront(reason);
diff --git a/services/core/java/com/android/server/wm/ActivityRecord.java b/services/core/java/com/android/server/wm/ActivityRecord.java
index 38e8785..ad76af6 100644
--- a/services/core/java/com/android/server/wm/ActivityRecord.java
+++ b/services/core/java/com/android/server/wm/ActivityRecord.java
@@ -3401,6 +3401,16 @@
                 stack.checkKeyguardVisibility(this, true /* shouldBeVisible */, true /* isTop */);
     }
 
+    /**
+     * Check if this activity is able to resume. For pre-Q apps, only the topmost activities of each
+     * process are allowed to be resumed.
+     *
+     * @return true if this activity can be resumed.
+     */
+    boolean canResumeByCompat() {
+        return app == null || app.updateTopResumingActivityInProcessIfNeeded(this);
+    }
+
     boolean getTurnScreenOnFlag() {
         return mTurnScreenOn;
     }
diff --git a/services/core/java/com/android/server/wm/ActivityStack.java b/services/core/java/com/android/server/wm/ActivityStack.java
index 16c44aa..6fc2014 100644
--- a/services/core/java/com/android/server/wm/ActivityStack.java
+++ b/services/core/java/com/android/server/wm/ActivityStack.java
@@ -2597,6 +2597,10 @@
             return false;
         }
 
+        if (!next.canResumeByCompat()) {
+            return false;
+        }
+
         // If we are sleeping, and there is no resumed activity, and the top
         // activity is paused, well that is the state we want.
         if (shouldSleepOrShutDownActivities()
diff --git a/services/core/java/com/android/server/wm/ActivityStackSupervisor.java b/services/core/java/com/android/server/wm/ActivityStackSupervisor.java
index c8a150b..c0fe6e9 100644
--- a/services/core/java/com/android/server/wm/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/wm/ActivityStackSupervisor.java
@@ -720,6 +720,11 @@
 
             r.setProcess(proc);
 
+            // Ensure activity is allowed to be resumed after process has set.
+            if (andResume && !r.canResumeByCompat()) {
+                andResume = false;
+            }
+
             if (getKeyguardController().isKeyguardLocked()) {
                 r.notifyUnknownVisibilityLaunched();
             }
diff --git a/services/core/java/com/android/server/wm/RootActivityContainer.java b/services/core/java/com/android/server/wm/RootActivityContainer.java
index 624fdc2..ecab1f1 100644
--- a/services/core/java/com/android/server/wm/RootActivityContainer.java
+++ b/services/core/java/com/android/server/wm/RootActivityContainer.java
@@ -777,11 +777,8 @@
             // First the front stacks. In case any are not fullscreen and are in front of home.
             for (int displayNdx = mActivityDisplays.size() - 1; displayNdx >= 0; --displayNdx) {
                 final ActivityDisplay display = mActivityDisplays.get(displayNdx);
-                for (int stackNdx = display.getChildCount() - 1; stackNdx >= 0; --stackNdx) {
-                    final ActivityStack stack = display.getChildAt(stackNdx);
-                    stack.ensureActivitiesVisibleLocked(starting, configChanges, preserveWindows,
-                            notifyClients);
-                }
+                display.ensureActivitiesVisible(starting, configChanges, preserveWindows,
+                        notifyClients);
             }
         } finally {
             mStackSupervisor.getKeyguardController().endActivityVisibilityUpdate();
diff --git a/services/core/java/com/android/server/wm/TaskTapPointerEventListener.java b/services/core/java/com/android/server/wm/TaskTapPointerEventListener.java
index dd94af6..4ff552e 100644
--- a/services/core/java/com/android/server/wm/TaskTapPointerEventListener.java
+++ b/services/core/java/com/android/server/wm/TaskTapPointerEventListener.java
@@ -22,6 +22,8 @@
 import static android.view.PointerIcon.TYPE_TOP_RIGHT_DIAGONAL_DOUBLE_ARROW;
 import static android.view.PointerIcon.TYPE_VERTICAL_DOUBLE_ARROW;
 
+import static com.android.server.wm.ActivityStackSupervisor.PRESERVE_WINDOWS;
+
 import android.graphics.Rect;
 import android.graphics.Region;
 import android.hardware.input.InputManager;
@@ -86,6 +88,16 @@
                 if (parent != null && parent.getTopChild() != mDisplayContent) {
                     parent.positionChildAt(WindowContainer.POSITION_TOP, mDisplayContent,
                             true /* includingParents */);
+                    // For compatibility, only the topmost activity is allowed to be resumed for
+                    // pre-Q app. Ensure the topmost activities are resumed whenever a display is
+                    // moved to top.
+                    // TODO(b/123761773): Investigate whether we can move this into
+                    // RootActivityContainer#updateTopResumedActivityIfNeeded(). Currently, it is
+                    // risky to do so because it seems possible to resume activities as part of a
+                    // larger transaction and it's too early to resume based on current order
+                    // when performing updateTopResumedActivityIfNeeded().
+                    mDisplayContent.mAcitvityDisplay.ensureActivitiesVisible(null /* starting */,
+                            0 /* configChanges */, !PRESERVE_WINDOWS, true /* notifyClients */);
                 }
             }
         };
diff --git a/services/core/java/com/android/server/wm/WindowProcessController.java b/services/core/java/com/android/server/wm/WindowProcessController.java
index 37e2200..0fb900a 100644
--- a/services/core/java/com/android/server/wm/WindowProcessController.java
+++ b/services/core/java/com/android/server/wm/WindowProcessController.java
@@ -17,6 +17,7 @@
 package com.android.server.wm;
 
 import static android.app.ActivityManager.PROCESS_STATE_NONEXISTENT;
+import static android.os.Build.VERSION_CODES.Q;
 import static android.view.Display.INVALID_DISPLAY;
 
 import static com.android.server.am.ActivityManagerService.MY_PID;
@@ -32,11 +33,11 @@
 import static com.android.server.wm.ActivityTaskManagerDebugConfig.POSTFIX_RELEASE;
 import static com.android.server.wm.ActivityTaskManagerDebugConfig.TAG_ATM;
 import static com.android.server.wm.ActivityTaskManagerDebugConfig.TAG_WITH_CLASS_NAME;
-import static com.android.server.wm.ActivityTaskManagerService
-        .INSTRUMENTATION_KEY_DISPATCHING_TIMEOUT_MS;
+import static com.android.server.wm.ActivityTaskManagerService.INSTRUMENTATION_KEY_DISPATCHING_TIMEOUT_MS;
 import static com.android.server.wm.ActivityTaskManagerService.KEY_DISPATCHING_TIMEOUT_MS;
 import static com.android.server.wm.ActivityTaskManagerService.RELAUNCH_REASON_NONE;
 
+import android.annotation.NonNull;
 import android.app.Activity;
 import android.app.ActivityThread;
 import android.app.IApplicationThread;
@@ -155,6 +156,8 @@
     private final ArrayList<ActivityRecord> mActivities = new ArrayList<>();
     // any tasks this process had run root activities in
     private final ArrayList<TaskRecord> mRecentTasks = new ArrayList<>();
+    // The most recent top-most activity that was resumed in the process for pre-Q app.
+    private ActivityRecord mPreQTopResumedActivity = null;
 
     // Last configuration that was reported to the process.
     private final Configuration mLastReportedConfiguration;
@@ -462,6 +465,59 @@
         }
     }
 
+    /**
+     * Update the top resuming activity in process for pre-Q apps, only the top-most visible
+     * activities are allowed to be resumed per process.
+     * @return {@code true} if the activity is allowed to be resumed by compatibility
+     * restrictions, which the activity was the topmost visible activity in process or the app is
+     * targeting after Q.
+     */
+    boolean updateTopResumingActivityInProcessIfNeeded(@NonNull ActivityRecord activity) {
+        if (mInfo.targetSdkVersion >= Q || mPreQTopResumedActivity == activity) {
+            return true;
+        }
+
+        final ActivityDisplay display = activity.getDisplay();
+        if (display == null) {
+            // No need to update if the activity hasn't attach to any display.
+            return false;
+        }
+
+        boolean canUpdate = false;
+        final ActivityDisplay topDisplay =
+                mPreQTopResumedActivity != null ? mPreQTopResumedActivity.getDisplay() : null;
+        // Update the topmost activity if current top activity was not on any display or no
+        // longer visible.
+        if (topDisplay == null || !mPreQTopResumedActivity.visible) {
+            canUpdate = true;
+        }
+
+        // Update the topmost activity if the current top activity wasn't on top of the other one.
+        if (!canUpdate && topDisplay.mDisplayContent.compareTo(display.mDisplayContent) < 0) {
+            canUpdate = true;
+        }
+
+        // Compare the z-order of ActivityStacks if both activities landed on same display.
+        if (display == topDisplay
+                && mPreQTopResumedActivity.getActivityStack().mTaskStack.compareTo(
+                activity.getActivityStack().mTaskStack) <= 0) {
+            canUpdate = true;
+        }
+
+        if (canUpdate) {
+            // Make sure the previous top activity in the process no longer be resumed.
+            if (mPreQTopResumedActivity != null && mPreQTopResumedActivity.isState(RESUMED)) {
+                final ActivityStack stack = mPreQTopResumedActivity.getActivityStack();
+                if (stack != null) {
+                    stack.startPausingLocked(false /* userLeaving */, false /* uiSleeping */,
+                            null /* resuming */, false /* pauseImmediately */);
+                }
+            }
+            mPreQTopResumedActivity = activity;
+        }
+        return canUpdate;
+    }
+
     public void stopFreezingActivities() {
         synchronized (mAtm.mGlobalLock) {
             int i = mActivities.size();