Fix race condition where chrome.tabs.executeScript sometimes wouldn't

chrome/renderer/navigation_state.h

 // Copyright (c) 2009 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_RENDERER_NAVIGATION_STATE_H_
 #define CHROME_RENDERER_NAVIGATION_STATE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 48 matching lines @@
   }
 
   static NavigationState* FromDataSource(WebKit::WebDataSource* ds) {
     return static_cast<NavigationState*>(ds->extraData());
   }
 
   UserScriptIdleScheduler* user_script_idle_scheduler() {
     return user_script_idle_scheduler_.get();
   }
   void set_user_script_idle_scheduler(UserScriptIdleScheduler* scheduler);
+  void swap_user_script_idle_scheduler(NavigationState* state);
 
   // Contains the page_id for this navigation or -1 if there is none yet.
   int32 pending_page_id() const { return pending_page_id_; }
 
   // If pending_page_id() is not -1, then this contains the corresponding
   // offset of the page in the back/forward history list.
   int pending_history_list_offset() const {
     return pending_history_list_offset_;
   }
 
@@ skipping 228 matching lines @@
   bool was_within_same_page_;
 
   // A prefetcher is a page that contains link rel=prefetch elements.
   bool was_prefetcher_;
   bool was_referred_by_prefetcher_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationState);
 };
 
 #endif  // CHROME_RENDERER_NAVIGATION_STATE_H_