Revert of Remove the is_loading_ field from WebContentsImpl

content/test/web_contents_observer_sanity_checker.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.
 
 #ifndef CONTENT_TEST_WEB_CONTENTS_OBSERVER_SANITY_CHECKER_H_
 #define CONTENT_TEST_WEB_CONTENTS_OBSERVER_SANITY_CHECKER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 70 matching lines @@
                            RenderFrameHost* source_render_frame_host,
                            const GURL& url,
                            const Referrer& referrer,
                            WindowOpenDisposition disposition,
                            ui::PageTransition transition) override;
   void MediaStartedPlaying(const MediaPlayerId& id) override;
   void MediaStoppedPlaying(const MediaPlayerId& id) override;
   bool OnMessageReceived(const IPC::Message& message,
                          RenderFrameHost* render_frame_host) override;
   void WebContentsDestroyed() override;
-  void DidStartLoading() override;
-  void DidStopLoading() override;
 
  private:
   explicit WebContentsObserverSanityChecker(WebContents* web_contents);
   ~WebContentsObserverSanityChecker() override;
 
   std::string Format(RenderFrameHost* render_frame_host);
   void AssertRenderFrameExists(RenderFrameHost* render_frame_host);
   void AssertMainFrameExists();
 
   bool NavigationIsOngoing(NavigationHandle* navigation_handle);
 
   void EnsureStableParentValue(RenderFrameHost* render_frame_host);
   bool HasAnyChildren(RenderFrameHost* render_frame_host);
 
   std::set<GlobalRoutingID> current_hosts_;
   std::set<GlobalRoutingID> live_routes_;
   std::set<GlobalRoutingID> deleted_routes_;
 
   std::set<NavigationHandle*> ongoing_navigations_;
   std::vector<MediaPlayerId> active_media_players_;
 
   // Remembers parents to make sure RenderFrameHost::GetParent() never changes.
   std::map<GlobalRoutingID, GlobalRoutingID> parent_ids_;
 
-  bool is_loading_;
-
   bool web_contents_destroyed_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsObserverSanityChecker);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_WEB_CONTENTS_OBSERVER_SANITY_CHECKER_H_