Animation start scale should be considered for the raster scale

cc/animation/layer_animation_controller.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_
 #define CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/ref_counted.h"
@@ skipping 116 matching lines @@
                                    gfx::BoxF* bounds) const;
   bool TransformAnimationBoundsForBox(const gfx::BoxF& box,
                                       gfx::BoxF* bounds) const;
 
   bool HasAnimationThatAffectsScale() const;
 
   bool HasOnlyTranslationTransforms() const;
 
   bool AnimationsPreserveAxisAlignment() const;
 
+  // Sets |start_scale| to the maximum of starting animation scale along any
+  // dimension at any destination in active animations. Returns false if the
+  // starting scale cannot be computed.
+  bool AnimationStartScale(float* start_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;
 
   // When a scroll animation is removed on the main thread, its compositor
   // thread counterpart continues producing scroll deltas until activation.
   // These scroll deltas need to be cleared at activation, so that the active
   // layer's scroll offset matches the offset provided by the main thread
   // rather than a combination of this offset and scroll deltas produced by
@@ skipping 75 matching lines @@
   bool needs_to_start_animations_;
 
   bool scroll_offset_animation_was_interrupted_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerAnimationController);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_