Create a new action triggered when a BeginMainFrame is not expected before vsync

cc/scheduler/scheduler.cc

Index: cc/scheduler/scheduler.cc
diff --git a/cc/scheduler/scheduler.cc b/cc/scheduler/scheduler.cc
index 40294b8a3a6a9d6ce77b5a8c25e7a1bf0897c68e..b9d62225947b61de65c306af8aa892e10a9da7e0 100644
--- a/cc/scheduler/scheduler.cc
+++ b/cc/scheduler/scheduler.cc
@@ -208,6 +208,11 @@ base::TimeTicks Scheduler::LastBeginImplFrameTime() {
   return begin_impl_frame_tracker_.Current().frame_time;
 }
 
+void Scheduler::BeginMainFrameNotExpectedUntil(base::TimeTicks time) {
+  TRACE_EVENT0("cc", "Scheduler::BeginMainFrameNotExpectedUntil");

[sunnyps, 2017/04/20 18:36:47]

nit: might want to log time in the trace event

[Dan Elphick, 2017/04/26 16:31:44]

Done.

+  client_->ScheduledActionBeginMainFrameNotExpectedUntil(time);
+}
+
 void Scheduler::BeginImplFrameNotExpectedSoon() {
   compositor_timing_history_->BeginImplFrameNotExpectedSoon();
 
@@ -629,6 +634,11 @@ void Scheduler::ProcessScheduledActions() {
         // TODO(brianderson): Pass begin_main_frame_args_ directly to client.
         client_->ScheduledActionSendBeginMainFrame(begin_main_frame_args_);
         break;
+      case SchedulerStateMachine::ACTION_NOTIFY_BEGIN_MAIN_FRAME_NOT_SENT:
+        state_machine_.WillNotifyBeginMainFrameNotSent();
+        BeginMainFrameNotExpectedUntil(begin_main_frame_args_.frame_time +
+                                       begin_main_frame_args_.interval);
+        break;
       case SchedulerStateMachine::ACTION_COMMIT: {
         bool commit_has_no_updates = false;
         state_machine_.WillCommit(commit_has_no_updates);