ui: Use a PaintRecorder to access the Canvas for painting.

ui/aura/demo/demo_main.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 "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/i18n/icu_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/power_monitor/power_monitor.h"
 #include "base/power_monitor/power_monitor_device_source.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/aura/client/default_capture_client.h"
 #include "ui/aura/client/window_tree_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/test/test_focus_client.h"
 #include "ui/aura/test/test_screen.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/base/hit_test.h"
-#include "ui/compositor/paint_context.h"
+#include "ui/compositor/paint_recorder.h"
 #include "ui/compositor/test/in_process_context_factory.h"
 #include "ui/events/event.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gl/gl_surface.h"
 
 #if defined(USE_X11)
 #include "ui/gfx/x/x11_connection.h"
 #endif
@@ skipping 24 matching lines @@
     return HTCAPTION;
   }
   bool ShouldDescendIntoChildForEventHandling(
       aura::Window* child,
       const gfx::Point& location) override {
     return true;
   }
   bool CanFocus() override { return true; }
   void OnCaptureLost() override {}
   void OnPaint(const ui::PaintContext& context) override {
-    gfx::Canvas* canvas = context.canvas();
-    canvas->DrawColor(color_, SkXfermode::kSrc_Mode);
+    ui::PaintRecorder recorder(context);
+    recorder.canvas()->DrawColor(color_, SkXfermode::kSrc_Mode);
     gfx::Rect r;
-    canvas->GetClipBounds(&r);
+    recorder.canvas()->GetClipBounds(&r);
     // Fill with a non-solid color so that the compositor will exercise its
     // texture upload path.
     while (!r.IsEmpty()) {
       r.Inset(2, 2);
-      canvas->FillRect(r, color_, SkXfermode::kXor_Mode);
+      recorder.canvas()->FillRect(r, color_, SkXfermode::kXor_Mode);
     }
   }
   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:
@@ skipping 104 matching lines @@
 int main(int argc, char** argv) {
   base::CommandLine::Init(argc, argv);
 
   // The exit manager is in charge of calling the dtors of singleton objects.
   base::AtExitManager exit_manager;
 
   base::i18n::InitializeICU();
 
   return DemoMain();
 }