Run load state update timer only when needed

content/public/browser/web_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 CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_H_
 
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 287 matching lines @@
   // Returns whether this WebContents is loading and and the load is to a
   // different top-level document (rather than being a navigation within the
   // same document). This being true implies that IsLoading() is also true.
   virtual bool IsLoadingToDifferentDocument() const = 0;
 
   // Returns whether this WebContents is waiting for a first-response for the
   // main resource of the page.
   virtual bool IsWaitingForResponse() const = 0;
 
   // Returns the current load state and the URL associated with it.
+  // The load state is only updated while IsLoading() is true.
   virtual const net::LoadStateWithParam& GetLoadState() const = 0;
   virtual const base::string16& GetLoadStateHost() const = 0;
 
   // Returns the upload progress.
   virtual uint64 GetUploadSize() const = 0;
   virtual uint64 GetUploadPosition() const = 0;
 
   // Returns a set of the site URLs currently committed in this tab.
   virtual std::set<GURL> GetSitesInTab() const = 0;
 
@@ skipping 341 matching lines @@
 
  private:
   // This interface should only be implemented inside content.
   friend class WebContentsImpl;
   WebContents() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_H_