Rasterize at maximum scale for scale animations on CPU-rasterized layers

cc/layers/image_layer.cc

 // Copyright 2010 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.
 
 #include "cc/layers/image_layer.h"
 
 #include "base/compiler_specific.h"
 #include "cc/resources/image_layer_updater.h"
 #include "cc/resources/layer_updater.h"
 #include "cc/resources/prioritized_resource.h"
@@ skipping 49 matching lines @@
       layer_tree_host()->GetRendererCapabilities().best_texture_format);
 }
 
 LayerUpdater* ImageLayer::Updater() const {
   return updater_.get();
 }
 
 void ImageLayer::CalculateContentsScale(float ideal_contents_scale,
                                         float device_scale_factor,
                                         float page_scale_factor,
+                                        float maximum_animation_contents_scale,
                                         bool animating_transform_to_screen,
                                         float* contents_scale_x,
                                         float* contents_scale_y,
                                         gfx::Size* content_bounds) {
   *contents_scale_x = ImageContentsScaleX();
   *contents_scale_y = ImageContentsScaleY();
   *content_bounds = gfx::Size(bitmap_.width(), bitmap_.height());
 }
 
 bool ImageLayer::DrawsContent() const {
@@ skipping 12 matching lines @@
   return static_cast<float>(bitmap_.width()) / bounds().width();
 }
 
 float ImageLayer::ImageContentsScaleY() const {
   if (bounds().IsEmpty() || bitmap_.height() == 0)
     return 1;
   return static_cast<float>(bitmap_.height()) / bounds().height();
 }
 
 }  // namespace cc