Add the new window item to the Files.app's context menu on the launcher.

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",
     "description": "none",
     "types": [
       {
@@ skipping 1135 matching lines @@
               {
                 "name": "result",
                 "type": "boolean",
                 "description": "true if the length is in the valid range, false otherwise."
               }
             ]
           }
         ]
       },
       {
-        "name": "openNewWindow",
-        "description": "Opens a new window of the Files.app.",
-        "parameters": [
-          {
-            "name": "url",
-            "type": "string",
-            "description": "Internal url to be opened."
-          }
-        ]
-      },
-      {
         "name": "zoom",
         "description": "Changes the zoom factor of the Files.app.",
         "parameters": [
           {
             "name": "operation",
             "type": "string",
             "enum": ["in", "out", "reset"]
           }
         ]
       }
@@ skipping 56 matching lines @@
       },
       {
         "name": "onDriveConnectionStatusChanged",
         "type": "function",
         "description": "Fired when the active network connection state changes. The network connection state can be retrieved via 'getDriveConnectionState'.",
         "parameters": []
       }
     ]
   }
 ]