Web expose FileSystemFileEntry, FileSystemDirectoryEntry and friends

extensions/common/api/runtime.json

 // Copyright 2014 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.
 
 // Note: Many of these functions and events are implemented by hand and should
 // not elicit any code generation from the schema compiler. These items are
 // marked "nocompile."
 [
   {
     "namespace": "runtime",
@@ skipping 391 matching lines @@
                 "name": "platformInfo",
                 "$ref": "PlatformInfo"
               }
             ]
           }
         ]
       },
       {
         "name": "getPackageDirectoryEntry",
         "type": "function",
-        "description": "Returns a DirectoryEntry for the package directory.",
+        "description": "Returns a FileSystemDirectoryEntry for the package directory.",
         "parameters": [
           {
             "type": "function",
             "name": "callback",
             "parameters": [
               {
                 "name": "directoryEntry",
                 "type": "object",
                 "additionalProperties": { "type": "any" },
-                "isInstanceOf": "DirectoryEntry"
+                "isInstanceOf": "FileSystemDirectoryEntry"
               }
             ]
           }
         ]
       }
     ],
     "events": [
       {
         "name": "onStartup",
         "type": "function",
@@ skipping 128 matching lines @@
           {
             "$ref": "OnRestartRequiredReason",
             "name": "reason",
             "description": "The reason that the event is being dispatched."
           }
         ]
       }
     ]
   }
 ]