Pass a ui::PaintContext from ui::Layer to layer delegates.

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 <algorithm>
 #include <map>
 #include <set>
@@ skipping 1093 matching lines @@
   // recurses through all children. This is used when adding a layer to an
   // existing view to make sure all descendants that have layers are parented to
   // the right layer.
   void MoveLayerToParent(ui::Layer* parent_layer, const gfx::Point& point);
 
   // Called to update the bounds of any child layers within this View's
   // hierarchy when something happens to the hierarchy.
   void UpdateChildLayerBounds(const gfx::Vector2d& offset);
 
   // Overridden from ui::LayerDelegate:
-  void OnPaintLayer(gfx::Canvas* canvas) override;
+  void OnPaintLayer(const ui::PaintContext& context) override;
   void OnDelegatedFrameDamage(const gfx::Rect& damage_rect_in_dip) override;
   void OnDeviceScaleFactorChanged(float device_scale_factor) override;
   base::Closure PrepareForLayerBoundsChange() override;
 
   // Finds the layer that this view paints to (it may belong to an ancestor
   // view), then reorders the immediate children of that layer to match the
   // order of the view tree.
   virtual void ReorderLayers();
 
   // This reorders the immediate children of |*parent_layer| to match the
@@ skipping 439 matching lines @@
   // Belongs to this view, but it's reference-counted on some platforms
   // so we can't use a scoped_ptr. It's dereferenced in the destructor.
   NativeViewAccessibility* native_view_accessibility_;
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_H_