Switch Extensions::TabHelper to use WebContents, WebContentsUserData.

chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/location_bar/location_bar_view_mac.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
@@ skipping 606 matching lines @@
     return;
   }
 
   TabContents* tab_contents = GetTabContents();
   if (!tab_contents) {
     DeletePageActionDecorations();  // Necessary?
     return;
   }
 
   std::vector<ExtensionAction*> new_page_actions =
-      tab_contents->extension_tab_helper()->location_bar_controller()->
-          GetCurrentActions();
+      extensions::TabHelper::FromWebContents(tab_contents->web_contents())->
+          location_bar_controller()->GetCurrentActions();
 
   if (new_page_actions != page_actions_) {
     page_actions_.swap(new_page_actions);
     DeletePageActionDecorations();
     for (size_t i = 0; i < page_actions_.size(); ++i) {
       page_action_decorations_.push_back(
           new PageActionDecoration(this, browser_, page_actions_[i]));
     }
   }
 
@@ skipping 128 matching lines @@
     visible = false;
   star_decoration_->SetVisible(visible);
 }
 
 void LocationBarViewMac::UpdatePlusDecorationVisibility() {
   if (extensions::switch_utils::IsActionBoxEnabled()) {
     // If the action box is enabled, hide it when input is in progress.
     plus_decoration_->SetVisible(!toolbar_model_->input_in_progress());
   }
 }