cc: Compute animation scale on demand

cc/trees/draw_property_utils.cc

 // Copyright 2014 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/trees/draw_property_utils.h"
 
 #include <stddef.h>
 
 #include <vector>
 
@@ skipping 1191 matching lines @@
       ScreenSpaceTransformInternal(layer, property_trees->transform_tree);
   if (property_trees->non_root_surfaces_enabled) {
     layer->draw_properties().target_space_transform =
         DrawTransform(layer, property_trees->transform_tree);
   } else {
     layer->draw_properties().target_space_transform =
         layer->draw_properties().screen_space_transform;
   }
   layer->draw_properties().screen_space_transform_is_animating =
       transform_node->data.to_screen_is_potentially_animated;
-  if (layer->layer_tree_impl()
-          ->settings()
-          .layer_transforms_should_scale_layer_contents) {
-    layer->draw_properties().maximum_animation_contents_scale =
-        transform_node->data.combined_maximum_animation_target_scale;
-    layer->draw_properties().starting_animation_contents_scale =
-        transform_node->data.combined_starting_animation_scale;
-  } else {
-    layer->draw_properties().maximum_animation_contents_scale = 0.f;
-    layer->draw_properties().starting_animation_contents_scale = 0.f;

[ajuma, 2016/06/29 15:04:37]

Please make sure the new logic also uses scale 0 when
layer_transforms_should_scale_layer_contents is false (and please add a test for
this if we don't already have one).

[sunxd, 2016/06/30 15:29:44]

Done.

-  }
 
   layer->draw_properties().opacity =
       LayerDrawOpacity(layer, property_trees->effect_tree);
   if (property_trees->non_root_surfaces_enabled) {
     layer->draw_properties().is_clipped = clip_node->data.layers_are_clipped;
   } else {
     layer->draw_properties().is_clipped =
         clip_node->data.layers_are_clipped_when_surfaces_disabled;
   }
 
@@ skipping 139 matching lines @@
 void UpdateElasticOverscroll(PropertyTrees* property_trees,
                              const Layer* overscroll_elasticity_layer,
                              const gfx::Vector2dF& elastic_overscroll) {
   UpdateElasticOverscrollInternal(property_trees, overscroll_elasticity_layer,
                                   elastic_overscroll);
 }
 
 }  // namespace draw_property_utils
 
 }  // namespace cc