Switch WebNavigationTabObserver to use WebContentsUserData.

chrome/browser/ui/tab_contents/tab_contents.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_H_
 #define CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
@@ skipping 57 matching lines @@
 class SyncedTabDelegate;
 }
 
 namespace chromeos {
 class SimpleWebViewDialog;
 class WebUILoginView;
 }
 
 namespace extensions {
 class WebAuthFlow;
-class WebNavigationTabObserver;
 }
 
 namespace prerender {
 class PrerenderContents;
 class PrerenderTabHelper;
 }
 
 namespace safe_browsing {
 class SafeBrowsingTabObserver;
 }
@@ skipping 195 matching lines @@
 
   // Handles displaying a web intents picker to the user.
   scoped_ptr<WebIntentPickerController> web_intent_picker_controller_;
 
   scoped_ptr<ZoomController> zoom_controller_;
 
   // Per-tab observers ---------------------------------------------------------
   // (These provide no API for callers; objects that need to exist 1:1 with tabs
   // and silently do their thing live here.)
 
-  scoped_ptr<extensions::WebNavigationTabObserver> webnavigation_observer_;
   scoped_ptr<ExternalProtocolObserver> external_protocol_observer_;
   scoped_ptr<NavigationMetricsRecorder> navigation_metrics_recorder_;
   scoped_ptr<PepperBrokerObserver> pepper_broker_observer_;
   scoped_ptr<PluginObserver> plugin_observer_;
   scoped_ptr<safe_browsing::SafeBrowsingTabObserver>
       safe_browsing_tab_observer_;
 
   // WebContents (MUST BE LAST) ------------------------------------------------
 
   // If true, we're running the destructor.
   bool in_destructor_;
 
   // The supporting objects need to outlive the WebContents dtor (as they may
   // be called upon during its execution). As a result, this must come last
   // in the list.
   scoped_ptr<content::WebContents> web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(TabContents);
 };
 
 #endif  // CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_H_