Revert "Gallery: use native header."

ui/file_manager/gallery/js/background.js

 // 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.
 
 /**
  * Configuration of the Gallery window.
  * @const
  * @type {Object}
  */
 var windowCreateOptions = {
   id: 'gallery',
-  outerBounds: {
+  innerBounds: {
     minWidth: 820,
     minHeight: 554
   },
-  frame: {
-    color: '#1E2023'
-  }
+  frame: 'none'
 };
 
 /**
  * Backgound object. This is necessary for AppWindowWrapper.
  * @type {!BackgroundBase}
  */
 var background = new BackgroundBase();
 
 /**
  * Wrapper of gallery window.
@@ skipping 86 matching lines @@
       });
     });
   }).then(function(gallery) {
     gallery.rawAppWindow.focus();
     return gallery.rawAppWindow.contentWindow.appID;
   }).catch(function(error) {
     console.error('Launch failed' + error.stack || error);
     return Promise.reject(error);
   });
 }