Introduce PlatformBitmap, which is a minimal helper class that wraps an SkBitmap

chrome/browser/thumbnails/thumbnail_tab_helper.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/browser/thumbnails/thumbnail_tab_helper.h"
 
 #include "base/metrics/histogram.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/history/top_sites.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 386 matching lines @@
   gfx::Rect copy_rect = gfx::Rect(view->GetViewBounds().size());
   // Clip the pixels that will commonly hold a scrollbar, which looks bad in
   // thumbnails.
   int scrollbar_size = gfx::scrollbar_size();
   copy_rect.Inset(0, 0, scrollbar_size, scrollbar_size);
   ClipResult clip_result = ThumbnailTabHelper::kUnprocessed;
   copy_rect = GetClippingRect(copy_rect.size(),
                               gfx::Size(kThumbnailWidth, kThumbnailHeight),
                               &clip_result);
   gfx::Size copy_size = GetCopySizeForThumbnail(view);
-  skia::PlatformCanvas* temp_canvas = new skia::PlatformCanvas;
+  skia::PlatformBitmap* temp_bitmap = new skia::PlatformBitmap;
   render_widget_host->CopyFromBackingStore(
       copy_rect,
       copy_size,
       base::Bind(&ThumbnailTabHelper::UpdateThumbnailWithCanvas,
                  weak_factory_.GetWeakPtr(),
                  web_contents,
                  clip_result,
-                 base::Owned(temp_canvas)),
-      temp_canvas);
+                 base::Owned(temp_bitmap)),
+      temp_bitmap);
 }
 
 void ThumbnailTabHelper::UpdateThumbnailWithBitmap(
     WebContents* web_contents,
     ClipResult clip_result,
     const SkBitmap& bitmap) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   if (bitmap.isNull() || bitmap.empty())
     return;
 
   SkBitmap thumbnail = CreateThumbnail(bitmap,
                                        GetThumbnailSizeInPixel(),
                                        &clip_result);
   UpdateThumbnail(web_contents, thumbnail, clip_result);
 }
 
 void ThumbnailTabHelper::UpdateThumbnailWithCanvas(
     WebContents* web_contents,
     ClipResult clip_result,
-    skia::PlatformCanvas* temp_canvas,
+    skia::PlatformBitmap* temp_bitmap,
     bool succeeded) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   if (!succeeded)
     return;
 
-  SkBitmap bitmap = skia::GetTopDevice(*temp_canvas)->accessBitmap(false);
+  SkBitmap bitmap = temp_bitmap->GetBitmap();
   UpdateThumbnailWithBitmap(web_contents, clip_result, bitmap);
 }
 
 bool ThumbnailTabHelper::ShouldUpdateThumbnail(Profile* profile,
                                                history::TopSites* top_sites,
                                                const GURL& url) {
   if (!profile || !top_sites)
     return false;
   // Skip if it's in the incognito mode.
   if (profile->IsOffTheRecord())
@@ skipping 22 matching lines @@
 void ThumbnailTabHelper::DidStartLoading(
     content::RenderViewHost* render_view_host) {
   load_interrupted_ = false;
 }
 
 void ThumbnailTabHelper::StopNavigation() {
   // This function gets called when the page loading is interrupted by the
   // stop button.
   load_interrupted_ = true;
 }