Optionally clear PlatformCanvas instances.

chrome/renderer/safe_browsing/phishing_thumbnailer.cc

 // Copyright (c) 2010 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/safe_browsing/phishing_thumbnailer.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "content/public/renderer/render_view.h"
@@ skipping 15 matching lines @@
 
 SkBitmap GrabPhishingThumbnail(content::RenderView* render_view,
                                const gfx::Size& view_size,
                                const gfx::Size& thumbnail_size) {
   if (!render_view || !render_view->GetWebView()) {
     return SkBitmap();  // The WebView is going away.
   }
   WebView* view = render_view->GetWebView();
   base::TimeTicks beginning_time = base::TimeTicks::Now();
   skia::PlatformCanvas canvas;
-  if (!canvas.initialize(view_size.width(), view_size.height(), true)) {
+  if (!canvas.initialize(view_size.width(), view_size.height(),
+                         skia::PlatformDevice::FLAGS_OPAQUE)) {
     return SkBitmap();
   }
 
   // Make sure we are not using any zoom when we take the snapshot.  We will
   // restore the previous zoom level after the snapshot is taken.
   double old_zoom_level = view->zoomLevel();
   if (view->zoomLevel() != 0.0) {
     view->setZoomLevel(false, 0.0);
   }
   WebSize old_size = view->size();
@@ skipping 24 matching lines @@
   view->mainFrame()->setCanHaveScrollbars(
       render_view->ShouldDisplayScrollbars(old_size.width, old_size.height));
   view->resize(old_size);
 
   UMA_HISTOGRAM_TIMES("SBClientPhishing.GrabPhishingThumbnail",
                       base::TimeTicks::Now() - beginning_time);
   return thumbnail;
 }
 
 }  // namespace safe_browsing