cc : Add OnOpacityAnimated to effect tree

cc/trees/property_tree.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 <stddef.h>
 
 #include <set>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 895 matching lines @@
                              transform_tree.device_transform_scale_factor();
   TransformNode* transform_node =
       transform_tree.Node(effect_node->transform_id);
   if (transform_node->in_subtree_of_page_scale_layer)
     layer_scale_factor *= transform_tree.page_scale_factor();
   effect_node->surface_contents_scale =
       MathUtil::ComputeTransform2dScaleComponents(
           transform_tree.ToScreen(transform_node->id), layer_scale_factor);
 }
 
+void EffectTree::OnOpacityAnimated(float opacity,
+                                   int id,
+                                   LayerTreeImpl* layer_tree_impl) {
+  EffectNode* node = Node(id);
+  if (node->opacity == opacity)
+    return;
+  node->opacity = opacity;
+  node->effect_changed = true;
+  property_trees()->changed = true;
+  property_trees()->effect_tree.set_needs_update(true);
+  layer_tree_impl->set_needs_update_draw_properties();
+  layer_tree_impl->AddToOpacityAnimationsMap(node->owner_id, opacity);
+}
+
 void EffectTree::UpdateEffects(int id) {
   EffectNode* node = Node(id);
   EffectNode* parent_node = parent(node);
 
   UpdateOpacities(node, parent_node);
   UpdateIsDrawn(node, parent_node);
   UpdateEffectChanged(node, parent_node);
   UpdateBackfaceVisibility(node, parent_node);
   UpdateSurfaceContentsScale(node);
 }
@@ skipping 1263 matching lines @@
     from_target.ConcatTransform(draw_transforms.from_target);
     from_target.Scale(effect_node->surface_contents_scale.x(),
                       effect_node->surface_contents_scale.y());
     DCHECK(from_target.ApproximatelyEqual(*transform) ||
            !draw_transforms.invertible);
   }
   return success;
 }
 
 }  // namespace cc