Refactoring the way begin frame sources inside scheduler work.

cc/trees/single_thread_proxy.cc

Index: cc/trees/single_thread_proxy.cc
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index a920f5a28ac25e3425de7d50ff0f7ca0df5fffe1..33680470119cc5bdcbf6ff5930d121785a42ad54 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -104,9 +104,6 @@ void SingleThreadProxy::SetVisible(bool visible) {
   TRACE_EVENT0("cc", "SingleThreadProxy::SetVisible");
   DebugScopedSetImplThread impl(this);
   layer_tree_host_impl_->SetVisible(visible);
-
-  // Changing visibility could change ShouldComposite().
-  UpdateBackgroundAnimateTicking();
 }
 
 void SingleThreadProxy::CreateAndInitializeOutputSurface() {
@@ -255,7 +252,6 @@ void SingleThreadProxy::OnCanDrawStateChanged(bool can_draw) {
   TRACE_EVENT1(
       "cc", "SingleThreadProxy::OnCanDrawStateChanged", "can_draw", can_draw);
   DCHECK(Proxy::IsImplThread());
-  UpdateBackgroundAnimateTicking();
 }
 
 void SingleThreadProxy::NotifyReadyToActivate() {
@@ -454,12 +450,6 @@ bool SingleThreadProxy::ShouldComposite() const {
          layer_tree_host_impl_->CanDraw();
 }
 
-void SingleThreadProxy::UpdateBackgroundAnimateTicking() {

[brianderson, 2014/05/07 18:09:59]

Well this is annoying. SingleThreadProxy is going to need a separate solution to
background ticking (outside the Scheduler) until it becomes a SchedulerClient.
Maybe we can't delete the old background ticking logic yet?

[mithro-old, 2014/05/07 22:02:32]

Unsure yet. Do you know if there are unit tests which make sure this all works?

[brianderson, 2014/05/08 00:55:58]

The LayerTreeHost/Impl unit tests should test background ticking. Most of them
run in both threaded and non-threaded modes.

[mithro-old, 2014/05/09 02:45:58]

Guess we will find out shortly.

-  DCHECK(Proxy::IsImplThread());
-  layer_tree_host_impl_->UpdateBackgroundAnimateTicking(
-      !ShouldComposite() && layer_tree_host_impl_->active_tree()->root_layer());
-}
-
 bool SingleThreadProxy::DoComposite(
     base::TimeTicks frame_begin_time,
     const gfx::Rect& device_viewport_damage_rect,
@@ -480,13 +470,11 @@ bool SingleThreadProxy::DoComposite(
     // DrawLayers() depends on the result of PrepareToDraw(), it is guarded on
     // CanDraw() as well.
     if (!ShouldComposite() || (for_readback && !can_do_readback)) {
-      UpdateBackgroundAnimateTicking();
       return false;
     }
 
     layer_tree_host_impl_->Animate(
         layer_tree_host_impl_->CurrentFrameTimeTicks());
-    UpdateBackgroundAnimateTicking();
 
     if (!layer_tree_host_impl_->IsContextLost()) {
       layer_tree_host_impl_->PrepareToDraw(frame, device_viewport_damage_rect);