Expose the chrome.windows.* API to platform apps.

chrome/common/extensions/api/windows.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": "windows",
     "dependencies": [ "tabs" ],
     "types": [
       {
@@ skipping 158 matching lines @@
               "left": {"type": "integer", "optional": true, "description": "The number of pixels to position the new window from the left edge of the screen. If not specified, the new window is offset naturally from the last focused window. This value is ignored for panels."},
               "top": {"type": "integer", "optional": true, "description": "The number of pixels to position the new window from the top edge of the screen. If not specified, the new window is offset naturally from the last focused window. This value is ignored for panels."},
               "width": {"type": "integer", "minimum": 0, "optional": true, "description": "The width in pixels of the new window. If not specified defaults to a natural width."},
               "height": {"type": "integer", "minimum": 0, "optional": true, "description": "The height in pixels of the new window. If not specified defaults to a natural height."},
               "focused": {"type": "boolean", "optional": true, "description": "If true, opens an active window. If false, opens an inactive window."},
               "incognito": {"type": "boolean", "optional": true, "description": "Whether the new window should be an incognito window."},
               "type": {
                 "type": "string",
                 "optional": true,
                 "description": "Specifies what type of browser window to create. The 'panel' type creates a popup unless the '--enable-panels' flag is set.",
-                "enum": ["normal", "popup", "panel"]
+                "enum": ["normal", "popup", "panel", "shell"]
               }
             },
             "optional": true
           },
           {
             "type": "function",
             "name": "callback",
             "optional": true,
             "parameters": [
               {
@@ skipping 75 matching lines @@
         "name": "onFocusChanged",
         "type": "function",
         "description": "Fired when the currently focused window changes. Will be chrome.windows.WINDOW_ID_NONE if all chrome windows have lost focus. Note: On some Linux window managers, WINDOW_ID_NONE will always be sent immediately preceding a switch from one chrome window to another.",
         "parameters": [
           {"type": "integer", "name": "windowId", "minimum": -1, "description": "ID of the newly focused window."}
         ]
       }
     ]
   }
 ]