Drive: Add "Clear Local Cache" in the Gear menu to clear all local cache of Drive.

chrome/browser/chromeos/extensions/file_browser_private_api.cc

 // 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.
 
 #include "chrome/browser/chromeos/extensions/file_browser_private_api.h"
 
 #include <utility>
 
 #include "base/base64.h"
 #include "base/bind.h"
@@ skipping 1580 matching lines @@
   SET_STRING(IDS_FILE_BROWSER, CONFIRM_DELETE_ONE);
   SET_STRING(IDS_FILE_BROWSER, CONFIRM_DELETE_SOME);
 
   SET_STRING(IDS_FILE_BROWSER, UNKNOWN_FILESYSTEM_WARNING);
   SET_STRING(IDS_FILE_BROWSER, UNSUPPORTED_FILESYSTEM_WARNING);
   SET_STRING(IDS_FILE_BROWSER, FORMATTING_WARNING);
 
   SET_STRING(IDS_FILE_BROWSER, GDATA_MENU_HELP);
   SET_STRING(IDS_FILE_BROWSER, GDATA_SHOW_HOSTED_FILES_OPTION);
   SET_STRING(IDS_FILE_BROWSER, GDATA_MOBILE_CONNECTION_OPTION);
+  SET_STRING(IDS_FILE_BROWSER, GDATA_CLEAR_LOCAL_CACHE);
   SET_STRING(IDS_FILE_BROWSER, GDATA_SPACE_AVAILABLE);
   SET_STRING(IDS_FILE_BROWSER, GDATA_WAITING_FOR_SPACE_INFO);
   SET_STRING(IDS_FILE_BROWSER, GDATA_FAILED_SPACE_INFO);
   SET_STRING(IDS_FILE_BROWSER, GDATA_BUY_MORE_SPACE);
 
   SET_STRING(IDS_FILE_BROWSER, SELECT_FOLDER_TITLE);
   SET_STRING(IDS_FILE_BROWSER, SELECT_OPEN_FILE_TITLE);
   SET_STRING(IDS_FILE_BROWSER, SELECT_OPEN_MULTI_FILE_TITLE);
   SET_STRING(IDS_FILE_BROWSER, SELECT_SAVEAS_FILE_TITLE);
 
@@ skipping 803 matching lines @@
   gdata::GDataSystemService* system_service =
       gdata::GDataSystemServiceFactory::GetForProfile(profile_);
   if (!system_service || !system_service->file_system())
     return false;
 
   FilePath directory_path = GetVirtualPathFromURL(GURL(file_url_as_string));
   system_service->file_system()->RequestDirectoryRefresh(directory_path);
 
   return true;
 }