cc: Compute animation scale on demand

cc/layers/picture_layer_impl.cc

 // 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.
 
 #include "cc/layers/picture_layer_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1007 matching lines @@
   // If we're not re-rasterizing during animation, rasterize at the maximum
   // scale that will occur during the animation, if the maximum scale is
   // known. However we want to avoid excessive memory use. If the scale is
   // smaller than what we would choose otherwise, then it's always better off
   // for us memory-wise. But otherwise, we don't choose a scale at which this
   // layer's rastered content would become larger than the viewport.
   if (draw_properties().screen_space_transform_is_animating &&
       !ShouldAdjustRasterScaleDuringScaleAnimations()) {
     bool can_raster_at_maximum_scale = false;
     bool should_raster_at_starting_scale = false;
-    float maximum_scale = draw_properties().maximum_animation_contents_scale;
-    float starting_scale = draw_properties().starting_animation_contents_scale;
+    CombinedAnimationScale animation_scales =
+        layer_tree_impl()->property_trees()->GetAnimationScales(
+            transform_tree_index(), layer_tree_impl());
+    float maximum_scale = animation_scales.maximum_animation_scale;
+    float starting_scale = animation_scales.starting_animation_scale;
     if (maximum_scale) {
       gfx::Size bounds_at_maximum_scale =
           gfx::ScaleToCeiledSize(raster_source_->GetSize(), maximum_scale);
       int64_t maximum_area =
           static_cast<int64_t>(bounds_at_maximum_scale.width()) *
           static_cast<int64_t>(bounds_at_maximum_scale.height());
       gfx::Size viewport = layer_tree_impl()->device_viewport_size();
       int64_t viewport_area = static_cast<int64_t>(viewport.width()) *
                               static_cast<int64_t>(viewport.height());
       if (maximum_area <= viewport_area)
@@ skipping 261 matching lines @@
 bool PictureLayerImpl::IsOnActiveOrPendingTree() const {
   return !layer_tree_impl()->IsRecycleTree();
 }
 
 bool PictureLayerImpl::HasValidTilePriorities() const {
   return IsOnActiveOrPendingTree() &&
          is_drawn_render_surface_layer_list_member();
 }
 
 }  // namespace cc