cc: Make PictureLayerImpl use a better choice for animated raster scale.

cc/animation/layer_animation_controller.h

Index: cc/animation/layer_animation_controller.h
diff --git a/cc/animation/layer_animation_controller.h b/cc/animation/layer_animation_controller.h
index e57491ac43c46a26e8fe018becc6d98a4db6bed1..01fce98c466b596e568d4ddeb75af24a35ca818c 100644
--- a/cc/animation/layer_animation_controller.h
+++ b/cc/animation/layer_animation_controller.h
@@ -134,9 +134,10 @@ class CC_EXPORT LayerAnimationController
 
   bool HasOnlyTranslationTransforms() const;
 
-  // Sets |max_scale| to the maximum scale along any dimension during active
-  // animations. Returns false if the maximum scale cannot be computed.
-  bool MaximumScale(float* max_scale) const;
+  // Sets |max_scale| to the maximum scale along any dimension at any
+  // destination in active animations. Returns false if the maximum scale cannot
+  // be computed.
+  bool MaximumTargetScale(float* max_scale) const;
 
   bool needs_to_start_animations_for_testing() {
     return needs_to_start_animations_;