Drive: Adds clearDriveCache API to file_browser_private.

chrome/common/extensions/api/file_browser_private.json

 // 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.
 
 [
   {
     "namespace":"fileBrowserPrivate",
     "nodoc": "true",
     "types": [
       {
@@ skipping 927 matching lines @@
                   "type": "object",
                   "isInstanceOf": "Entry",
                   "description": "Entry representing a search result."
                 }  
               }
             ]
           }
         ]
       },
       {
+        "name": "clearDriveCache",
+        "description": "Clear all GData local caches.",
+        "parameters": []
+      },
+      {
         "name": "getNetworkConnectionState",
         "description": "Retrieves the state of the currently active network connection.",
         "parameters": [
           {
             "name": "callback",
             "type": "function",
             "parameters": [
               {
                 "name": "result",
                 "type": "object",
@@ skipping 88 matching lines @@
       },
       {
         "name": "onNetworkConnectionChanged",
         "type": "function",
         "description": "Fired when the active network connection state changes. The network connection state can be retrieved via 'getNetworkConnectionState'.",
         "parameters": []
       }
     ]
   }
 ]