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

chrome/browser/extensions/extension_webstore_private_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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBSTORE_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBSTORE_PRIVATE_API_H_
 #pragma once
 
 #include <string>
 
@@ skipping 24 matching lines @@
 
 class BeginInstallWithManifestFunction
     : public AsyncExtensionFunction,
       public ExtensionInstallUI::Delegate,
       public WebstoreInstallHelper::Delegate {
  public:
   BeginInstallWithManifestFunction();
 
   // Result codes for the return value. If you change this, make sure to
   // update the description for the beginInstallWithManifest3 callback in
-  // extension_api.json.
+  // api/.
   enum ResultCode {
     ERROR_NONE = 0,
 
     // An unspecified error occurred.
     UNKNOWN_ERROR,
 
     // The user cancelled the confirmation dialog instead of accepting it.
     USER_CANCELLED,
 
     // The manifest failed to parse correctly.
@@ skipping 97 matching lines @@
   virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("webstorePrivate.getStoreLogin");
 };
 
 class SetStoreLoginFunction : public SyncExtensionFunction {
   virtual bool RunImpl() OVERRIDE;
   DECLARE_EXTENSION_FUNCTION_NAME("webstorePrivate.setStoreLogin");
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_WEBSTORE_PRIVATE_API_H_