SurfaceFlinger: Add DISPLAY_EVENT_FRAME_RATE_OVERRIDE

Add a new event to DisplayEventReceiver that conveys a list
of apps whose frame rates have been overriden.
This event is processed by the DisplayManager to advertise the
new frame rate to the overridden app.

Change-Id: I89fce8b5b4d9db65ec5db7dd2393c384c0fcfd82
Bug: 169271059
Bug: 169271062
Bug: 170503758
Test: manual test using SF backdoor
diff --git a/libs/gui/DisplayEventDispatcher.cpp b/libs/gui/DisplayEventDispatcher.cpp
index abfee61..c6c9a8f 100644
--- a/libs/gui/DisplayEventDispatcher.cpp
+++ b/libs/gui/DisplayEventDispatcher.cpp
@@ -33,10 +33,10 @@
 // using just a few large reads.
 static const size_t EVENT_BUFFER_SIZE = 100;
 
-DisplayEventDispatcher::DisplayEventDispatcher(const sp<Looper>& looper,
-                                               ISurfaceComposer::VsyncSource vsyncSource,
-                                               ISurfaceComposer::ConfigChanged configChanged)
-      : mLooper(looper), mReceiver(vsyncSource, configChanged), mWaitingForVsync(false) {
+DisplayEventDispatcher::DisplayEventDispatcher(
+        const sp<Looper>& looper, ISurfaceComposer::VsyncSource vsyncSource,
+        ISurfaceComposer::EventRegistrationFlags eventRegistration)
+      : mLooper(looper), mReceiver(vsyncSource, eventRegistration), mWaitingForVsync(false) {
     ALOGV("dispatcher %p ~ Initializing display event dispatcher.", this);
 }
 
@@ -139,6 +139,7 @@
     ssize_t n;
     while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) {
         ALOGV("dispatcher %p ~ Read %d events.", this, int(n));
+        mFrameRateOverrides.reserve(n);
         for (ssize_t i = 0; i < n; i++) {
             const DisplayEventReceiver::Event& ev = buf[i];
             switch (ev.header.type) {
@@ -162,6 +163,13 @@
                 case DisplayEventReceiver::DISPLAY_EVENT_NULL:
                     dispatchNullEvent(ev.header.timestamp, ev.header.displayId);
                     break;
+                case DisplayEventReceiver::DISPLAY_EVENT_FRAME_RATE_OVERRIDE:
+                    mFrameRateOverrides.emplace_back(ev.frameRateOverride);
+                    break;
+                case DisplayEventReceiver::DISPLAY_EVENT_FRAME_RATE_OVERRIDE_FLUSH:
+                    dispatchFrameRateOverrides(ev.header.timestamp, ev.header.displayId,
+                                               std::move(mFrameRateOverrides));
+                    break;
                 default:
                     ALOGW("dispatcher %p ~ ignoring unknown event type %#x", this, ev.header.type);
                     break;