Move the "extension" namespace from extension_api.json into extension_api_extension.json.

chrome/browser/extensions/extension_webnavigation_api.h

 // Copyright (c) 2011 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.
 
 // Defines the Chrome Extensions WebNavigation API functions for observing and
-// intercepting navigation events, as specified in
-// chrome/common/extensions/api/extension_api.json.
+// intercepting navigation events, as specified in the extension JSON API.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBNAVIGATION_API_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBNAVIGATION_API_H_
 #pragma once
 
 #include <map>
 #include <set>
 
 #include "base/compiler_specific.h"
 #include "chrome/browser/extensions/extension_function.h"
@@ skipping 221 matching lines @@
 };
 
 // API function that returns the states of all frames in a given tab.
 class GetAllFramesFunction : public SyncExtensionFunction {
   virtual ~GetAllFramesFunction() {}
   virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("webNavigation.getAllFrames")
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBNAVIGATION_API_H_