cc: Split out BeginFrame needed verse proactive for commits.

cc/scheduler/scheduler_state_machine.cc

Index: cc/scheduler/scheduler_state_machine.cc
diff --git a/cc/scheduler/scheduler_state_machine.cc b/cc/scheduler/scheduler_state_machine.cc
index ccf6b14e08e97b9dd8821ffc03a9be79635398aa..b28c03b42853f2a5c840ec1b1c2726bf1ea22c86 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -418,6 +418,10 @@ bool SchedulerStateMachine::CouldSendBeginMainFrame() const {
 }
 
 bool SchedulerStateMachine::ShouldSendBeginMainFrame() const {
+  // If begin frames are not needed, we shouldn't be sending an BeginMainFrame.
+  if (!BeginFrameNeeded())
+    return false;
+
   if (!CouldSendBeginMainFrame())
     return false;
 
@@ -437,8 +441,7 @@ bool SchedulerStateMachine::ShouldSendBeginMainFrame() const {
   // user input arriving soon.
   // TODO(brianderson): Allow sending BeginMainFrame while idle when the main
   // thread isn't consuming user input.
-  if (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_IDLE &&
-      BeginFrameNeeded())

[brianderson, 2014/12/19 23:34:06]

The check for BeginFrameNeeded is so we can commit activate and be ready to draw
before we request a BeginFrame from WebView.

I think Sunny's patch is a pre-req to this patch, and is likely why you were
seeing WebView test flake:
https://codereview.chromium.org/817603002

+  if (begin_impl_frame_state_ == BEGIN_IMPL_FRAME_STATE_IDLE)
     return false;
 
   // We need a new commit for the forced redraw. This honors the
@@ -697,9 +700,8 @@ bool SchedulerStateMachine::BeginFrameNeededForChildren() const {
 
 bool SchedulerStateMachine::BeginFrameNeeded() const {
   if (SupportsProactiveBeginFrame()) {
-    return (BeginFrameNeededToAnimateOrDraw() ||
-            BeginFrameNeededForChildren() ||
-            ProactiveBeginFrameWanted());
+    return (BeginFrameNeededToAnimateOrDrawOrCommit() ||
+            BeginFrameNeededForChildren() || ProactiveBeginFrameWanted());

[sunnyps, 2015/03/05 00:19:47]

OR needs_commit_ here.

   }
 
   // Proactive BeginFrames are bad for the synchronous compositor because we
@@ -709,7 +711,7 @@ bool SchedulerStateMachine::BeginFrameNeeded() const {
   // we rely on ShouldPollForAnticipatedDrawTriggers instead.
   // Synchronous compositor doesn't have a browser.
   DCHECK(!children_need_begin_frames_);
-  return BeginFrameNeededToAnimateOrDraw();
+  return BeginFrameNeededToAnimateOrDrawOrCommit();
 }
 
 bool SchedulerStateMachine::ShouldPollForAnticipatedDrawTriggers() const {
@@ -717,7 +719,8 @@ bool SchedulerStateMachine::ShouldPollForAnticipatedDrawTriggers() const {
   // ProactiveBeginFrameWanted when we are using the synchronous
   // compositor.
   if (!SupportsProactiveBeginFrame()) {
-    return !BeginFrameNeededToAnimateOrDraw() && ProactiveBeginFrameWanted();
+    return !BeginFrameNeededToAnimateOrDrawOrCommit() &&
+           ProactiveBeginFrameWanted();
   }
 
   // Non synchronous compositors should rely on
@@ -743,7 +746,7 @@ void SchedulerStateMachine::SetChildrenNeedBeginFrames(
 
 // These are the cases where we definitely (or almost definitely) have a
 // new frame to animate and/or draw and can draw.
-bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDraw() const {
+bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDrawOrCommit() const {
   // The output surface is the provider of BeginImplFrames, so we are not going
   // to get them even if we ask for them.
   if (!HasInitializedOutputSurface())
@@ -754,7 +757,7 @@ bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDraw() const {
   if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
     return true;
 
-  return needs_animate_ || needs_redraw_;
+  return needs_animate_ || needs_redraw_ || needs_commit_;

[sunnyps, 2015/03/05 00:19:47]

Remove needs_commit_ from here.

 }
 
 // These are cases where we are very likely to draw soon, but might not