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

ui/views/widget/widget_unittest.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 <algorithm>
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 1281 matching lines @@
   void Close() override {
     expect_paint_ = false;
     views::Widget::Close();
   }
 
   void Hide() {
     expect_paint_ = false;
     views::Widget::Hide();
   }
 
-  void OnNativeWidgetPaint(gfx::Canvas* canvas) override {
+  void OnNativeWidgetPaint(const ui::PaintContext& context) override {
     received_paint_ = true;
     EXPECT_TRUE(expect_paint_);
     if (!expect_paint_)
       received_paint_while_hidden_ = true;
-    views::Widget::OnNativeWidgetPaint(canvas);
+    views::Widget::OnNativeWidgetPaint(context);
   }
 
   bool ReadReceivedPaintAndReset() {
     bool result = received_paint_;
     received_paint_ = false;
     return result;
   }
 
   bool received_paint_while_hidden() const {
     return received_paint_while_hidden_;
@@ skipping 2013 matching lines @@
   bool handled = false;
   target->HandleKeyboardMessage(WM_CHAR, 0, 0, &handled);
   target->HandleKeyboardMessage(WM_SYSCHAR, 0, 0, &handled);
   target->HandleKeyboardMessage(WM_SYSDEADCHAR, 0, 0, &handled);
   widget.CloseNow();
 }
 #endif
 
 }  // namespace test
 }  // namespace views