cc: Make animations tick regardless of drawing.

cc/animation/layer_animation_controller.cc

Index: cc/animation/layer_animation_controller.cc
diff --git a/cc/animation/layer_animation_controller.cc b/cc/animation/layer_animation_controller.cc
index a213ba7f76bfaa67350b69fb5a7fd41c7049e63f..08ac1d5d797ef7ea2e6d9e36b3a47789dd50a119 100644
--- a/cc/animation/layer_animation_controller.cc
+++ b/cc/animation/layer_animation_controller.cc
@@ -174,15 +174,21 @@ void LayerAnimationController::AccumulatePropertyUpdates(
   }
 }
 
-void LayerAnimationController::UpdateState(AnimationEventsVector* events) {
+void LayerAnimationController::UpdateState(bool start_ready_animations,
+                                           AnimationEventsVector* events) {
   if (!HasActiveObserver())
     return;
 
-  PromoteStartedAnimations(last_tick_time_, events);
+  if (start_ready_animations)
+    PromoteStartedAnimations(last_tick_time_, events);
+
   MarkFinishedAnimations(last_tick_time_);
   MarkAnimationsForDeletion(last_tick_time_, events);
-  StartAnimationsWaitingForTargetAvailability(last_tick_time_);
-  PromoteStartedAnimations(last_tick_time_, events);
+
+  if (start_ready_animations) {
+    StartAnimationsWaitingForTargetAvailability(last_tick_time_);
+    PromoteStartedAnimations(last_tick_time_, events);
+  }
 
   AccumulatePropertyUpdates(last_tick_time_, events);