Add skia::RefPtr class to wrap ref counted classes from Skia.

chrome/renderer/chrome_render_view_observer.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 "chrome/renderer/chrome_render_view_observer.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 800 matching lines @@
   }
 }
 
 bool ChromeRenderViewObserver::CaptureSnapshot(WebView* view,
                                                SkBitmap* snapshot) {
   base::TimeTicks beginning_time = base::TimeTicks::Now();
 
   view->layout();
   const WebSize& size = view->size();
 
-  SkCanvas* canvas = skia::CreatePlatformCanvas(size.width, size.height, true,
-                                            NULL, skia::RETURN_NULL_ON_FAILURE);
+  skia::RefPtr<SkCanvas> canvas = skia::CreatePlatformCanvas(
+      size.width, size.height, true, NULL, skia::RETURN_NULL_ON_FAILURE);
   if (!canvas)
     return false;
 
-  SkAutoUnref au(canvas);
-  view->paint(webkit_glue::ToWebCanvas(canvas),
+  view->paint(webkit_glue::ToWebCanvas(canvas.get()),
               WebRect(0, 0, size.width, size.height));
   // TODO: Add a way to snapshot the whole page, not just the currently
   // visible part.
 
   SkDevice* device = skia::GetTopDevice(*canvas);
 
   const SkBitmap& bitmap = device->accessBitmap(false);
   if (!bitmap.copyTo(snapshot, SkBitmap::kARGB_8888_Config))
     return false;
 
   HISTOGRAM_TIMES("Renderer4.Snapshot",
                   base::TimeTicks::Now() - beginning_time);
   return true;
 }
 
 ExternalHostBindings* ChromeRenderViewObserver::GetExternalHostBindings() {
   if (!external_host_bindings_.get()) {
     external_host_bindings_.reset(new ExternalHostBindings(
         render_view(), routing_id()));
   }
   return external_host_bindings_.get();
 }
 
 bool ChromeRenderViewObserver::IsStrictSecurityHost(const std::string& host) {
   return (strict_security_hosts_.find(host) != strict_security_hosts_.end());
 }