Minor cleanups/fixes before virtual display refactoring

None of these should change behavior, except for removing some
incorrect log messages when using a virtual display.

- HWComposer::getAndResetReleaseFenceFd() checks the HWC version, so
  no need to do that in the DisplayDevice::onSwapBuffersCompleted().
  However, it should check that mFramebufferSurface is not NULL like
  it is for virtual displays.
- Comment that FramebufferSurface::dump() overrides the non-virtual
  ConsumerBase::dump(), and fix it so the right thing happens
  regardless of the static type of the pointer/reference the callee
  has. FramebufferSurface::dump() could be removed right now, but I'd
  need to bring it back in a later change.
- Use the right enum for validating display type ids.
- Don't try to send hotplug events for virtual displays.
- Mark virtual displays as connected so HWComposer::prepare() doesn't
  think something is wrong when it gets a non-NULL layer list.
- Remove unused FramebufferSurface methods.

Bug: 8384764
Change-Id: Id28a2f9be86b45f4bb7915fdf7752157035f4294
diff --git a/services/surfaceflinger/EventThread.cpp b/services/surfaceflinger/EventThread.cpp
index edb9fa5..4d0fc79 100644
--- a/services/surfaceflinger/EventThread.cpp
+++ b/services/surfaceflinger/EventThread.cpp
@@ -41,7 +41,7 @@
       mUseSoftwareVSync(false),
       mDebugVsyncEnabled(false) {
 
-    for (int32_t i=0 ; i<HWC_DISPLAY_TYPES_SUPPORTED ; i++) {
+    for (int32_t i=0 ; i<HWC_NUM_DISPLAY_TYPES ; i++) {
         mVSyncEvent[i].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC;
         mVSyncEvent[i].header.id = 0;
         mVSyncEvent[i].header.timestamp = 0;
@@ -112,11 +112,11 @@
 
 
 void EventThread::onVSyncReceived(int type, nsecs_t timestamp) {
-    ALOGE_IF(type >= HWC_DISPLAY_TYPES_SUPPORTED,
-            "received event for an invalid display (id=%d)", type);
+    ALOGE_IF(type >= HWC_NUM_DISPLAY_TYPES,
+            "received vsync event for an invalid display (id=%d)", type);
 
     Mutex::Autolock _l(mLock);
-    if (type < HWC_DISPLAY_TYPES_SUPPORTED) {
+    if (type < HWC_NUM_DISPLAY_TYPES) {
         mVSyncEvent[type].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC;
         mVSyncEvent[type].header.id = type;
         mVSyncEvent[type].header.timestamp = timestamp;
@@ -126,11 +126,11 @@
 }
 
 void EventThread::onHotplugReceived(int type, bool connected) {
-    ALOGE_IF(type >= HWC_DISPLAY_TYPES_SUPPORTED,
-            "received event for an invalid display (id=%d)", type);
+    ALOGE_IF(type >= HWC_NUM_DISPLAY_TYPES,
+            "received hotplug event for an invalid display (id=%d)", type);
 
     Mutex::Autolock _l(mLock);
-    if (type < HWC_DISPLAY_TYPES_SUPPORTED) {
+    if (type < HWC_NUM_DISPLAY_TYPES) {
         DisplayEventReceiver::Event event;
         event.header.type = DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG;
         event.header.id = type;
@@ -184,7 +184,7 @@
 
         size_t vsyncCount = 0;
         nsecs_t timestamp = 0;
-        for (int32_t i=0 ; i<HWC_DISPLAY_TYPES_SUPPORTED ; i++) {
+        for (int32_t i=0 ; i<HWC_NUM_DISPLAY_TYPES ; i++) {
             timestamp = mVSyncEvent[i].header.timestamp;
             if (timestamp) {
                 // we have a vsync event to dispatch