CC Animation: Rename Active Players to Ticking Players.

cc/trees/mutator_host.h

Index: cc/trees/mutator_host.h
diff --git a/cc/trees/mutator_host.h b/cc/trees/mutator_host.h
index bd3ed1d88a4e8f6ba781e14b1c832f0b0e66f6d3..8db5f6014ce75d34811887c6ca0e6355d1637f81 100644
--- a/cc/trees/mutator_host.h
+++ b/cc/trees/mutator_host.h
@@ -49,10 +49,10 @@ class MutatorHost {
   virtual void PushPropertiesTo(MutatorHost* host_impl) = 0;
 
   virtual void SetSupportsScrollAnimations(bool supports_scroll_animations) = 0;
-  virtual bool NeedsAnimateLayers() const = 0;
+  virtual bool NeedsTickAnimations() const = 0;
 
   virtual bool ActivateAnimations() = 0;
-  virtual bool AnimateLayers(base::TimeTicks monotonic_time) = 0;
+  virtual bool TickAnimations(base::TimeTicks monotonic_time) = 0;
   virtual bool UpdateAnimationState(bool start_ready_animations,
                                     MutatorEvents* events) = 0;
 
@@ -110,7 +110,7 @@ class MutatorHost {
                                    float* start_scale) const = 0;
 
   virtual bool HasAnyAnimation(ElementId element_id) const = 0;
-  virtual bool HasActiveAnimationForTesting(ElementId element_id) const = 0;
+  virtual bool HasTickingAnimationForTesting(ElementId element_id) const = 0;
 
   virtual void ImplOnlyScrollAnimationCreate(
       ElementId element_id,