Animation start scale should be considered for the raster scale

cc/layers/draw_properties.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_LAYERS_DRAW_PROPERTIES_H_
 #define CC_LAYERS_DRAW_PROPERTIES_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/trees/occlusion.h"
 #include "third_party/skia/include/core/SkXfermode.h"
@@ skipping 25 matching lines @@
         has_child_with_a_scroll_parent(false),
         sorted_for_recursion(false),
         visited(false),
         index_of_first_descendants_addition(0),
         num_descendants_added(0),
         index_of_first_render_surface_layer_list_addition(0),
         num_render_surfaces_added(0),
         last_drawn_render_surface_layer_list_id(0),
         ideal_contents_scale(0.f),
         maximum_animation_contents_scale(0.f),
+        starting_animation_contents_scale(0.f),
         page_scale_factor(0.f),
         device_scale_factor(0.f) {}
 
   // Transforms objects from content space to target surface space, where
   // this layer would be drawn.
   gfx::Transform target_space_transform;
 
   // Transforms objects from content space to screen space (viewport space).
   gfx::Transform screen_space_transform;
 
@@ skipping 93 matching lines @@
   int last_drawn_render_surface_layer_list_id;
 
   // The scale at which content for the layer should be rastered in order to be
   // perfectly crisp.
   float ideal_contents_scale;
 
   // The maximum scale during the layers current animation at which content
   // should be rastered at to be crisp.
   float maximum_animation_contents_scale;
 
+  // The scale during the layer animation start at which content should be
+  // rastered at to be crisp.
+  float starting_animation_contents_scale;
+
   // The page scale factor that is applied to the layer. Since some layers may
   // have page scale applied and others not, this may differ between layers.
   float page_scale_factor;
 
   // The device scale factor that is applied to the layer.
   float device_scale_factor;
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_DRAW_PROPERTIES_H_