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

ui/views/cocoa/bridged_native_widget.h

 // 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.
 
 #ifndef UI_VIEWS_COCOA_BRIDGED_NATIVE_WIDGET_H_
 #define UI_VIEWS_COCOA_BRIDGED_NATIVE_WIDGET_H_
 
 #import <Cocoa/Cocoa.h>
 #include <vector>
 
@@ skipping 182 matching lines @@
   // Creates and attaches a new instance if not found.
   NSMutableDictionary* GetWindowProperties() const;
 
   // Overridden from FocusChangeListener:
   void OnWillChangeFocus(View* focused_before,
                          View* focused_now) override;
   void OnDidChangeFocus(View* focused_before,
                         View* focused_now) override;
 
   // 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;
 
   // Overridden from ui::AcceleratedWidgetMac:
   NSView* AcceleratedWidgetGetNSView() const override;
   bool AcceleratedWidgetShouldIgnoreBackpressure() const override;
   void AcceleratedWidgetSwapCompleted(
       const std::vector<ui::LatencyInfo>& latency_info) override;
   void AcceleratedWidgetHitError() override;
@@ skipping 34 matching lines @@
   // If true, the window is either visible, or wants to be visible but is
   // currently hidden due to having a hidden parent.
   bool wants_to_be_visible_;
 
   DISALLOW_COPY_AND_ASSIGN(BridgedNativeWidget);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_COCOA_BRIDGED_NATIVE_WIDGET_H_