Add externs for gallery.

ui/file_manager/file_manager/common/js/externs.js

Index: ui/file_manager/file_manager/common/js/externs.js
diff --git a/ui/file_manager/file_manager/common/js/externs.js b/ui/file_manager/file_manager/common/js/externs.js
index 91a589c5e34450bf7dfe1c0c7bc2e1f8a708f8f2..3de10168e3bc0d460ca662945d4ff5f4e97e767d 100644
--- a/ui/file_manager/file_manager/common/js/externs.js
+++ b/ui/file_manager/file_manager/common/js/externs.js
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// TODO(yawano): Move all externs under ui/file_manager/externs.
+
 /**
  * @constructor
  * @extends {Window}
@@ -71,19 +73,6 @@ DirectoryChangeEvent.prototype.newDirEntry;
 DirectoryChangeEvent.prototype.volumeChanged;
 
 /**
- * @param {string} url
- * @param {function(!Entry)} successCallback
- * @param {function(!FileError)=} opt_errorCallback
- */
-Window.prototype.webkitResolveLocalFileSystemURL =
-    function(url, successCallback, opt_errorCallback) {};
-
-/**
- * @type {string}
- */
-Window.prototype.appID;
-
-/**
  * @type {boolean}
  */
 Window.prototype.closing;