Removed dead code from chrome/browser/extensions/api/web_navigation

chrome/browser/extensions/api/web_navigation/frame_navigation_state.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 CHROME_BROWSER_EXTENSIONS_API_WEB_NAVIGATION_FRAME_NAVIGATION_STATE_H_
 #define CHROME_BROWSER_EXTENSIONS_API_WEB_NAVIGATION_FRAME_NAVIGATION_STATE_H_
 
 #include <map>
 #include <set>
 
 #include "base/compiler_specific.h"
 #include "googleurl/src/gurl.h"
 
 namespace content {
 class RenderViewHost;
 }
 
 namespace extensions {
 
 // Tracks the navigation state of all frames in a given tab currently known to
 // the webNavigation API. It is mainly used to track in which frames an error
 // occurred so no further events for this frame are being sent.
 class FrameNavigationState {
  public:
   // A frame is uniquely identified by its frame ID and the RVH it's in.
   struct FrameID {
     FrameID();
     FrameID(int64 frame_num, content::RenderViewHost* render_view_host);
 
-    bool IsValid() const;
-
     bool operator<(const FrameID& other) const;
     bool operator==(const FrameID& other) const;
     bool operator!=(const FrameID& other) const;
 
     int64 frame_num;
     content::RenderViewHost* render_view_host;
   };
   typedef std::set<FrameID>::const_iterator const_iterator;
 
   FrameNavigationState();
@@ skipping 97 matching lines @@
 
   // If true, also allow events from chrome-extension:// URLs.
   static bool allow_extension_scheme_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameNavigationState);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_WEB_NAVIGATION_FRAME_NAVIGATION_STATE_H_