SurfaceFlinger: Shared timeline plumbing

Add plumbing to get shared timeline data from Surface Flinger to HWUI
and back.

Bug: 162890382
Bug: 162888881

Test: SF unit tests
Change-Id: Ifb76e6bf28d43c051e6c8ff568437ec9a106b865
diff --git a/libs/gui/DisplayEventDispatcher.cpp b/libs/gui/DisplayEventDispatcher.cpp
index 2cc7c34..7e894b4 100644
--- a/libs/gui/DisplayEventDispatcher.cpp
+++ b/libs/gui/DisplayEventDispatcher.cpp
@@ -73,7 +73,8 @@
         nsecs_t vsyncTimestamp;
         PhysicalDisplayId vsyncDisplayId;
         uint32_t vsyncCount;
-        if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) {
+        int64_t vsyncId;
+        if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount, &vsyncId)) {
             ALOGE("dispatcher %p ~ last event processed while scheduling was for %" PRId64 "", this,
                   ns2ms(static_cast<nsecs_t>(vsyncTimestamp)));
         }
@@ -116,11 +117,13 @@
     nsecs_t vsyncTimestamp;
     PhysicalDisplayId vsyncDisplayId;
     uint32_t vsyncCount;
-    if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount)) {
-        ALOGV("dispatcher %p ~ Vsync pulse: timestamp=%" PRId64 ", displayId=%s, count=%d", this,
-              ns2ms(vsyncTimestamp), to_string(vsyncDisplayId).c_str(), vsyncCount);
+    int64_t vsyncId;
+    if (processPendingEvents(&vsyncTimestamp, &vsyncDisplayId, &vsyncCount, &vsyncId)) {
+        ALOGV("dispatcher %p ~ Vsync pulse: timestamp=%" PRId64
+              ", displayId=%s, count=%d, vsyncId=%" PRId64,
+              this, ns2ms(vsyncTimestamp), to_string(vsyncDisplayId).c_str(), vsyncCount, vsyncId);
         mWaitingForVsync = false;
-        dispatchVsync(vsyncTimestamp, vsyncDisplayId, vsyncCount);
+        dispatchVsync(vsyncTimestamp, vsyncDisplayId, vsyncCount, vsyncId);
     }
 
     return 1; // keep the callback
@@ -128,10 +131,11 @@
 
 bool DisplayEventDispatcher::processPendingEvents(nsecs_t* outTimestamp,
                                                   PhysicalDisplayId* outDisplayId,
-                                                  uint32_t* outCount) {
+                                                  uint32_t* outCount, int64_t* outVsyncId) {
     bool gotVsync = false;
     DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE];
     ssize_t n;
+    *outVsyncId = 0;
     while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) {
         ALOGV("dispatcher %p ~ Read %d events.", this, int(n));
         for (ssize_t i = 0; i < n; i++) {
@@ -144,6 +148,7 @@
                     *outTimestamp = ev.header.timestamp;
                     *outDisplayId = ev.header.displayId;
                     *outCount = ev.vsync.count;
+                    *outVsyncId = ev.vsync.vsyncId;
                     break;
                 case DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG:
                     dispatchHotplug(ev.header.timestamp, ev.header.displayId, ev.hotplug.connected);