Switch Extensions::TabHelper to use WebContents, WebContentsUserData.

chrome/browser/sync/glue/session_change_processor.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/sync/glue/session_change_processor.h"
 
 #include <string>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 163 matching lines @@
         return;
       }
       modified_tabs.push_back(tab);
       DVLOG(1) << "Received NAV_ENTRY_COMMITTED for profile " << profile_;
       break;
     }
 
     case chrome::NOTIFICATION_TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED: {
       extensions::TabHelper* extension_tab_helper =
           content::Source<extensions::TabHelper>(source).ptr();
-      if (!extension_tab_helper ||
-          extension_tab_helper->web_contents()->GetBrowserContext() !=
+      if (extension_tab_helper->web_contents()->GetBrowserContext() !=
               profile_) {
         return;
       }
       if (extension_tab_helper->extension_app()) {
-        modified_tabs.push_back(extension_tab_helper->tab_contents()->
-            synced_tab_delegate());
+        TabContents* tab_contents =
+            TabContents::FromWebContents(extension_tab_helper->web_contents());
+        modified_tabs.push_back(tab_contents->synced_tab_delegate());
       }
       DVLOG(1) << "Received TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED "
                << "for profile " << profile_;
       break;
     }
 
     default:
       LOG(ERROR) << "Received unexpected notification of type "
                   << type;
       break;
@@ skipping 163 matching lines @@
   notification_registrar_.Add(this, chrome::NOTIFICATION_FAVICON_CHANGED,
       content::Source<Profile>(profile_));
 }
 
 void SessionChangeProcessor::StopObserving() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   notification_registrar_.RemoveAll();
 }
 
 }  // namespace browser_sync