Update SetPaintToLayer to accept LayerType

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 316 matching lines @@
 
   // Clipping is done relative to the view's local bounds.
   void set_clip_path(const gfx::Path& path) { clip_path_ = path; }
 
   // Sets the transform to the supplied transform.
   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(true) has been invoked.
+  // . SetPaintToLayer(ui::LayerType) has been invoked.
   // View creates the Layer only when it exists in a Widget with a non-NULL
   // Compositor.
-  void SetPaintToLayer(bool paint_to_layer);
+  void SetPaintToLayer(ui::LayerType layer_type = ui::LAYER_TEXTURED);
+
+  // Removes |view|'s layer if it has its own.
+  void DetachLayer();

[sky, 2017/01/23 17:10:08]

DetachLayer doesn't convey this destroys the layer. OTOH DestroyLayer or
DeleteLayer() better describe what this does. Please name this DestroyLayer()
and move the the implementation of View::DestroyLayer() to match new position.

 
   // 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 1011 matching lines @@
 
   // Convert a rect in the ancestor's coordinate system to the view's
   // coordinate system using necessary transformations. Returns whether the
   // rect was successfully converted from the ancestor's coordinate system
   // to the view's coordinate system.
   bool ConvertRectFromAncestor(const View* ancestor, gfx::RectF* rect) const;
 
   // Accelerated painting ------------------------------------------------------
 
   // Creates the layer and related fields for this view.
-  void CreateLayer();
+  void CreateLayer(ui::LayerType layer_type);
 
   // Recursively calls UpdateParentLayers() on all descendants, stopping at any
   // Views that have layers. Calls UpdateParentLayer() for any Views that have
   // a layer with no parent. If at least one descendant had an unparented layer
   // true is returned.
   bool UpdateParentLayers();
 
   // Parents this view's layer to |parent_layer|, and sets its bounds and other
   // properties in accordance to |offset|, the view's offset from the
   // |parent_layer|.
@@ skipping 230 matching lines @@
   // Observers -------------------------------------------------------------
 
   base::ObserverList<ViewObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_H_