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

ui/views/controls/native/native_view_host_aura.cc

 // 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.
 
 #include "ui/views/controls/native/native_view_host_aura.h"
 
 #include "base/logging.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
@@ skipping 33 matching lines @@
   }
   bool CanFocus() override {
     // Ask the hosted native view's delegate because directly calling
     // aura::Window::CanFocus() will call back into this when checking whether
     // parents can focus.
     return native_view_ && native_view_->delegate()
         ? native_view_->delegate()->CanFocus()
         : true;
   }
   void OnCaptureLost() override {}
-  void OnPaint(gfx::Canvas* canvas) override {}
+  void OnPaint(const ui::PaintContext& context) override {}
   void OnDeviceScaleFactorChanged(float device_scale_factor) override {}
   void OnWindowDestroying(aura::Window* window) override {}
   void OnWindowDestroyed(aura::Window* window) override {}
   void OnWindowTargetVisibilityChanged(bool visible) override {}
   bool HasHitTestMask() const override { return false; }
   void GetHitTestMask(gfx::Path* mask) const override {}
 
  private:
   aura::Window* native_view_;
 };
@@ skipping 164 matching lines @@
     } else {
       clipping_window_.RemoveChild(host_->native_view());
     }
     host_->native_view()->SetBounds(clipping_window_.bounds());
   }
   if (clipping_window_.parent())
     clipping_window_.parent()->RemoveChild(&clipping_window_);
 }
 
 }  // namespace views