cc : Track ids for which active opacity always wins on property trees

cc/layers/solid_color_scrollbar_layer.cc

 // Copyright 2013 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/solid_color_scrollbar_layer.h"
 
 #include <memory>
 
 #include "cc/layers/layer_impl.h"
 #include "cc/layers/solid_color_scrollbar_layer_impl.h"
@@ skipping 52 matching lines @@
 }
 
 void SolidColorScrollbarLayer::SetNeedsDisplayRect(const gfx::Rect& rect) {
   // Never needs repaint.
 }
 
 bool SolidColorScrollbarLayer::OpacityCanAnimateOnImplThread() const {
   return true;
 }
 
+bool SolidColorScrollbarLayer::AlwaysUseActiveTreeOpacity() const {
+  return true;
+}
+
 int SolidColorScrollbarLayer::ScrollLayerId() const {
   return scroll_layer_id_;
 }
 
 void SolidColorScrollbarLayer::SetScrollLayer(int layer_id) {
   if (layer_id == scroll_layer_id_)
     return;
 
   scroll_layer_id_ = layer_id;
   SetNeedsFullTreeSync();
@@ skipping 30 matching lines @@
       proto.solid_scrollbar();
   scroll_layer_id_ = scrollbar.scroll_layer_id();
   thumb_thickness_ = scrollbar.thumb_thickness();
   track_start_ = scrollbar.track_start();
   is_left_side_vertical_scrollbar_ =
       scrollbar.is_left_side_vertical_scrollbar();
   orientation_ = ScrollbarOrientationFromProto(scrollbar.orientation());
 }
 
 }  // namespace cc