Reland #2 Remove the is_loading_ field from WebContentsImpl

content/renderer/history_controller.h

 // Copyright 2014 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.
 
 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  *     (http://www.torchmobile.com/)
  *
  * Redistribution and use in source and binary forms, with or without
@@ skipping 99 matching lines @@
 //
 class CONTENT_EXPORT HistoryController {
  public:
   explicit HistoryController(RenderViewImpl* render_view);
   ~HistoryController();
 
   void set_provisional_entry(scoped_ptr<HistoryEntry> entry) {
     provisional_entry_ = std::move(entry);
   }
 
-  void GoToEntry(blink::WebLocalFrame* main_frame,
+  // Return true if the main frame ended up loading a request as part of the
+  // history navigation.
+  bool GoToEntry(blink::WebLocalFrame* main_frame,
                  scoped_ptr<HistoryEntry> entry,
                  scoped_ptr<NavigationParams> navigation_params,
                  blink::WebURLRequest::CachePolicy cache_policy);
 
   void UpdateForCommit(RenderFrameImpl* frame,
                        const blink::WebHistoryItem& item,
                        blink::WebHistoryCommitType commit_type,
                        bool navigation_within_page);
 
   HistoryEntry* GetCurrentEntry();
@@ skipping 26 matching lines @@
   // passed into frames created after the commit that resulted from the
   // navigation in GetItemForNewChildFrame().
   scoped_ptr<NavigationParams> navigation_params_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_HISTORY_CONTROLLER_H_