redo r137692 and r137791 which were speculatively reverted

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 396 matching lines @@
                 "items": {"$ref": "FileBrowserTask"},
                 "description": "The list of matched file URL patterns for this task."
               }
             ]
           }
         ]
       },
       {
         "name": "getStrings",
         "type": "function",
-        "description": "Gets Strings.",
+        "description": "Gets localized strings and initialization data.",
         "parameters": [
           {
             "type": "function",
-             "name": "callback",
-             "parameters": [
+            "name": "callback",
+            "parameters": [
               {
                 "name": "result",
                 "type": "object",
-                "additionalProperties": {"type": "string"}
+                "additionalProperties": { "type": "any" }
               }
             ]
           }
         ]
       },
       {
         "name": "addFileWatch",
         "description": "Adds file watch.",
         "parameters": [
           {
@@ skipping 567 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": []
       }
     ]
   }
 ]