Remove owning_id from EffectNode and replace it by an opaque stable_id

cc/input/scrollbar_animation_controller.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/input/scrollbar_animation_controller.h"
 
 #include <algorithm>
 
 #include "base/time/time.h"
 #include "cc/trees/layer_tree_impl.h"
@@ skipping 146 matching lines @@
 void ScrollbarAnimationController::RunAnimationFrame(float progress) {
   float opacity;
 
   DCHECK(animation_change_ != NONE);
   if (animation_change_ == FADE_IN) {
     opacity = std::max(progress, opacity_);
   } else {
     opacity = std::min(1.f - progress, opacity_);
   }
 
+  NotifyScrollbarLayersOfOpacityAnimation(opacity);
   ApplyOpacityToScrollbars(opacity);
   if (progress == 1.f)
     StopAnimation();
 }
 
 void ScrollbarAnimationController::DidScrollBegin() {
   currently_scrolling_ = true;
 }
 
 void ScrollbarAnimationController::DidScrollEnd() {
@@ skipping 146 matching lines @@
 }
 
 bool ScrollbarAnimationController::Captured() const {
   DCHECK(need_thinning_animation_);
   return GetScrollbarAnimationController(VERTICAL).captured() ||
          GetScrollbarAnimationController(HORIZONTAL).captured();
 }
 
 void ScrollbarAnimationController::Show() {
   delayed_scrollbar_animation_.Cancel();
+  NotifyScrollbarLayersOfOpacityAnimation(1.0f);
   ApplyOpacityToScrollbars(1.0f);
 }
 
-void ScrollbarAnimationController::ApplyOpacityToScrollbars(float opacity) {
+void ScrollbarAnimationController::NotifyScrollbarLayersOfOpacityAnimation(
+    float opacity) {
   for (ScrollbarLayerImplBase* scrollbar : Scrollbars()) {
     DCHECK(scrollbar->is_overlay_scrollbar());
     float effective_opacity = scrollbar->CanScrollOrientation() ? opacity : 0;
     scrollbar->SetOverlayScrollbarLayerOpacityAnimated(effective_opacity);
   }
+}
 
+void ScrollbarAnimationController::ApplyOpacityToScrollbars(float opacity) {
   bool previouslyVisible = opacity_ > 0.0f;
   bool currentlyVisible = opacity > 0.0f;
 
   if (opacity_ != opacity)
     client_->SetNeedsRedrawForScrollbarAnimation();
 
   opacity_ = opacity;
 
   if (previouslyVisible != currentlyVisible)
     client_->DidChangeScrollbarVisibility();
 }
 
 }  // namespace cc