Moving background animation ticking from LayerTreeHostImpl into the Scheduler.

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 439304aa3179cf10f4ba91c255346ecdc43acb14..94a6f2851c129f191776b57a31236a3970847bba 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -101,7 +101,6 @@ void SingleThreadProxy::SetVisible(bool visible) {
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->SetVisible(layer_tree_host_impl_->visible());
   // Changing visibility could change ShouldComposite().
-  UpdateBackgroundAnimateTicking();
 }
 
 void SingleThreadProxy::RequestNewOutputSurface() {
@@ -161,6 +160,24 @@ void SingleThreadProxy::SetNeedsUpdateLayers() {
   SetNeedsCommit();
 }
 
+void SingleThreadProxy::DoAnimate() {
+  // Don't animate if there is no root layer.
+  // TODO(mithro): Both Animate and UpdateAnimationState already have a
+  // "!active_tree_->root_layer()" check?
+  if (!layer_tree_host_impl_->active_tree()->root_layer()) {
+    return;
+  }
+
+  layer_tree_host_impl_->Animate(
+      layer_tree_host_impl_->CurrentBeginFrameArgs().frame_time);
+
+  // If animations are not visible, update the animation state now as it
+  // won't happen in DoComposite.
+  if (!layer_tree_host_impl_->AnimationsAreVisible()) {
+    layer_tree_host_impl_->UpdateAnimationState(true);
+  }
+}
+
 void SingleThreadProxy::DoCommit() {
   TRACE_EVENT0("cc", "SingleThreadProxy::DoCommit");
   DCHECK(Proxy::IsMainThread());
@@ -202,8 +219,6 @@ void SingleThreadProxy::DoCommit() {
 
     layer_tree_host_impl_->CommitComplete();
 
-    UpdateBackgroundAnimateTicking();
-
 #if DCHECK_IS_ON
     // In the single-threaded case, the scale and scroll deltas should never be
     // touched on the impl layer tree.
@@ -322,7 +337,6 @@ void SingleThreadProxy::OnCanDrawStateChanged(bool can_draw) {
   TRACE_EVENT1(
       "cc", "SingleThreadProxy::OnCanDrawStateChanged", "can_draw", can_draw);
   DCHECK(Proxy::IsImplThread());
-  UpdateBackgroundAnimateTicking();
   if (scheduler_on_impl_thread_)
     scheduler_on_impl_thread_->SetCanDraw(can_draw);
 }
@@ -341,7 +355,9 @@ void SingleThreadProxy::SetNeedsRedrawOnImplThread() {
 }
 
 void SingleThreadProxy::SetNeedsAnimateOnImplThread() {
-  SetNeedsRedrawOnImplThread();
+  client_->ScheduleComposite();
+  if (scheduler_on_impl_thread_)
+    scheduler_on_impl_thread_->SetNeedsAnimate();
 }
 
 void SingleThreadProxy::SetNeedsManageTilesOnImplThread() {
@@ -414,7 +430,6 @@ void SingleThreadProxy::DidActivateSyncTree() {
                    weak_factory_.GetWeakPtr()));
   }
 
-  UpdateBackgroundAnimateTicking();
   timing_history_.DidActivateSyncTree();
 }
 
@@ -492,6 +507,8 @@ void SingleThreadProxy::CompositeImmediately(base::TimeTicks frame_begin_time) {
       layer_tree_host_impl_->SynchronouslyInitializeAllTiles();
     }
 
+    DoAnimate();
+
     LayerTreeHostImpl::FrameData frame;
     DoComposite(frame_begin_time, &frame);
 
@@ -533,12 +550,6 @@ bool SingleThreadProxy::ShouldComposite() const {
          layer_tree_host_impl_->CanDraw();
 }
 
-void SingleThreadProxy::UpdateBackgroundAnimateTicking() {
-  DCHECK(Proxy::IsImplThread());
-  layer_tree_host_impl_->UpdateBackgroundAnimateTicking(
-      !ShouldComposite() && layer_tree_host_impl_->active_tree()->root_layer());
-}
-
 void SingleThreadProxy::ScheduleRequestNewOutputSurface() {
   if (output_surface_creation_callback_.IsCancelled() &&
       !output_surface_creation_requested_) {
@@ -566,16 +577,11 @@ DrawResult SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
     // DrawLayers() depends on the result of PrepareToDraw(), it is guarded on
     // CanDraw() as well.
     if (!ShouldComposite()) {
-      UpdateBackgroundAnimateTicking();
       return DRAW_ABORTED_CANT_DRAW;
     }
 
     timing_history_.DidStartDrawing();
 
-    layer_tree_host_impl_->Animate(
-        layer_tree_host_impl_->CurrentBeginFrameArgs().frame_time);
-    UpdateBackgroundAnimateTicking();
-
     draw_result = layer_tree_host_impl_->PrepareToDraw(frame);
     draw_frame = draw_result == DRAW_SUCCESS;
     if (draw_frame)
@@ -736,8 +742,8 @@ void SingleThreadProxy::ScheduledActionCommit() {
 
 void SingleThreadProxy::ScheduledActionAnimate() {
   TRACE_EVENT0("cc", "ScheduledActionAnimate");
-  layer_tree_host_impl_->Animate(
-      layer_tree_host_impl_->CurrentBeginFrameArgs().frame_time);
+  DebugScopedSetImplThread impl(this);
+  DoAnimate();
 }
 
 void SingleThreadProxy::ScheduledActionUpdateVisibleTiles() {