Ensure that the focus ring in the bookmarks bar does not paint outside the parent view.

ui/views/view.h

 // Copyright (c) 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.
 
 #ifndef UI_VIEWS_VIEW_H_
 #define UI_VIEWS_VIEW_H_
 
 #include <stddef.h>
 
 #include <algorithm>
@@ skipping 322 matching lines @@
   void SetTransform(const gfx::Transform& transform);
 
   // Sets whether this view paints to a layer. A view paints to a layer if
   // either of the following are true:
   // . the view has a non-identity transform.
   // . SetPaintToLayer(ui::LayerType) has been invoked.
   // View creates the Layer only when it exists in a Widget with a non-NULL
   // Compositor.
   void SetPaintToLayer(ui::LayerType layer_type = ui::LAYER_TEXTURED);
 
-  // Destroys the layer associated with this view, and reparents any descendants
-  // to the destroyed layer's parent. If the view does not currently have a
-  // layer, this has no effect.
+  // Please refer to the comments above the DestroyLayerImpl() function for
+  // details.
   void DestroyLayer();
 
   // Overridden from ui::LayerOwner:
   std::unique_ptr<ui::Layer> RecreateLayer() override;
 
   // RTL positioning -----------------------------------------------------------
 
   // Methods for accessing the bounds and position of the view, relative to its
   // parent. The position returned is mirrored if the parent view is using a RTL
   // layout.
@@ skipping 826 matching lines @@
   virtual void ReorderLayers();
 
   // This reorders the immediate children of |*parent_layer| to match the
   // order of the view tree. Child layers which are owned by a view are
   // reordered so that they are below any child layers not owned by a view.
   // Widget::ReorderNativeViews() should be called to reorder any child layers
   // with an associated view. Widget::ReorderNativeViews() may reorder layers
   // below layers owned by a view.
   virtual void ReorderChildLayers(ui::Layer* parent_layer);
 
+  // Notifies parents about a layer being created or destroyed in a child. An
+  // example where a subclass may override this method is when it wants to clip
+  // the child by adding its own layer.
+  virtual void OnChildLayerChanged(View* child);
+
+  enum class LayerChangeNotifyBehavior {

[sky, 2017/04/19 00:03:05]

Move this and the other functions (except for OnChildLayerChanged) to the
private 'Accelerated painting' section.

[ananta, 2017/04/19 00:53:17]

Done.

+    // Notify the parent chain about the layer change.
+    NOTIFY,
+    // Don't notify the parent chain about the layer change.
+    DONT_NOTIFY
+  };
+
+  // Destroys the layer associated with this view, and reparents any descendants
+  // to the destroyed layer's parent. If the view does not currently have a
+  // layer, this has no effect.
+  // The |notify_parents| enum controls whether a notification about the layer
+  // change is sent to the parents.
+  void DestroyLayerImpl(LayerChangeNotifyBehavior notify_parents);
+
+  // Notifies parents about layering changes in the view. This includes layer
+  // creation and destruction.
+  void NotifyParentsOfLayerChange();
+
   // Input ---------------------------------------------------------------------
 
   virtual DragInfo* GetDragInfo();
 
   // Focus ---------------------------------------------------------------------
 
   // Returns last set focus behavior.
   FocusBehavior focus_behavior() const { return focus_behavior_; }
 
   // Override to be notified when focus has changed either to or from this View.
@@ skipping 468 matching lines @@
   // Observers -------------------------------------------------------------
 
   base::ObserverList<ViewObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_H_