cc: Remove background ticking from LTHI.

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 c512987bd23f501abdaf1fceab783945f8dc1ae4..30139adda2fcfe0b202f6010c48fd4568ba680a2 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -677,6 +677,11 @@ bool SchedulerStateMachine::BeginFrameNeeded() const {
   if (!HasInitializedOutputSurface())
     return false;
 
+  // If we are not visible, we don't need BeginFrame messages.
+  if (!visible_) {

[brianderson, 2015/04/01 21:58:08]

Can you remove the visibility checks in BeginFrameNeededToAnimateOrDraw and
ProactiveBeginFrameWanted?

If the Renderers are requesting BeginFrames, we should probably give it to them
and move BeginFrameNeededForChildren() to before the !visible check. Otherwise,
DCHECK_IMPLIES(!visible, !BeginFrameNeededForChildren)?

[mithro-old, 2015/04/02 01:03:59]

I moved the !visible_ check into the BeginFrameNeededToAnimateOrDraw method
which I think fixes your concerns?

+    return false;
+  }
+
   if (SupportsProactiveBeginFrame()) {
     return (BeginFrameNeededToAnimateOrDraw() ||
             BeginFrameNeededForChildren() ||
@@ -827,9 +832,9 @@ bool SchedulerStateMachine::ShouldTriggerBeginImplFrameDeadlineImmediately()
   if (begin_impl_frame_state_ != BEGIN_IMPL_FRAME_STATE_INSIDE_BEGIN_FRAME)
     return false;
 
-  // If we've lost the output surface, end the current BeginImplFrame ASAP
-  // so we can start creating the next output surface.
-  if (output_surface_state_ == OUTPUT_SURFACE_LOST)
+  // If things are being aborted, end the current BeginImplFrame ASAP so we can
+  // unblock creating the next output surface.
+  if (PendingDrawsShouldBeAborted())

[brianderson, 2015/04/01 21:58:08]

This seems unrelated. Make this a separate patch?

[mithro-old, 2015/04/02 01:03:59]

Done.

     return true;
 
   // SwapAck throttle the deadline since we wont draw and swap anyway.