Load 2x resources on demand

chrome/browser/extensions/image_loading_tracker.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/extensions/image_loading_tracker.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 354 matching lines @@
     info->extension->SetCachedImage(image_info.resource,
                                     bitmap ? *bitmap : SkBitmap(),
                                     original_size);
   }
 
   // If all pending bitmaps are done then report back.
   if (info->pending_count == 0) {
     gfx::Image image;
     std::string extension_id = info->extension_id;
 
-    if (!info->image_skia.isNull())
+    if (!info->image_skia.isNull()) {
+      info->image_skia.SetReadOnly();
       image = gfx::Image(info->image_skia);
+    }
 
     load_map_.erase(load_map_it);
 
     // ImageLoadingTracker might be deleted after the callback so don't do
     // anything after this statement.
     observer_->OnImageLoaded(image, extension_id, id);
   }
 }
 
 void ImageLoadingTracker::Observe(int type,
                                   const content::NotificationSource& source,
                                   const content::NotificationDetails& details) {
   DCHECK(type == chrome::NOTIFICATION_EXTENSION_UNLOADED);
 
   const Extension* extension =
       content::Details<extensions::UnloadedExtensionInfo>(details)->extension;
 
   // Remove reference to this extension from all pending load entries. This
   // ensures we don't attempt to cache the bitmap when the load completes.
   for (LoadMap::iterator i = load_map_.begin(); i != load_map_.end(); ++i) {
     PendingLoadInfo* info = &i->second;
     if (info->extension == extension) {
       info->extension = NULL;
       info->cache = DONT_CACHE;
     }
   }
 }