cc: Remove retro frames from scheduler.

cc/surfaces/display_scheduler.cc

Index: cc/surfaces/display_scheduler.cc
diff --git a/cc/surfaces/display_scheduler.cc b/cc/surfaces/display_scheduler.cc
index 9f19fdcb41368395b62708889231501b6bdd7d3e..42ee80513df1cf64fe853c1b9125cac09b21ae69 100644
--- a/cc/surfaces/display_scheduler.cc
+++ b/cc/surfaces/display_scheduler.cc
@@ -59,7 +59,7 @@ void DisplayScheduler::ForceImmediateSwapIfPossible() {
   bool in_begin = inside_begin_frame_deadline_interval_;
   AttemptDrawAndSwap();
   if (in_begin)
-    begin_frame_source_->DidFinishFrame(0);
+    begin_frame_source_->DidFinishFrame(this);
 }
 
 void DisplayScheduler::DisplayResized() {
@@ -135,7 +135,11 @@ void DisplayScheduler::DrawAndSwap() {
   root_surface_damaged_ = false;
 }
 
-bool DisplayScheduler::OnBeginFrameDerivedImpl(const BeginFrameArgs& args) {
+const BeginFrameArgs& DisplayScheduler::LastUsedBeginFrameArgs() const {
+  return current_begin_frame_args_;
+}
+
+void DisplayScheduler::OnBeginFrame(const BeginFrameArgs& args) {
   base::TimeTicks now = base::TimeTicks::Now();
   TRACE_EVENT2("cc", "DisplayScheduler::BeginFrame", "args", args.AsValue(),
                "now", now);
@@ -152,8 +156,6 @@ bool DisplayScheduler::OnBeginFrameDerivedImpl(const BeginFrameArgs& args) {
       BeginFrameArgs::DefaultEstimatedParentDrawTime();
   inside_begin_frame_deadline_interval_ = true;
   ScheduleBeginFrameDeadline();
-
-  return true;
 }
 
 void DisplayScheduler::OnBeginFrameSourcePausedChanged(bool paused) {
@@ -293,7 +295,7 @@ void DisplayScheduler::OnBeginFrameDeadline() {
   TRACE_EVENT0("cc", "DisplayScheduler::OnBeginFrameDeadline");
 
   AttemptDrawAndSwap();
-  begin_frame_source_->DidFinishFrame(0);
+  begin_frame_source_->DidFinishFrame(this);
 }
 
 void DisplayScheduler::DidSwapBuffers() {