DevTools: Add support for adding folders to workspace with drag and drop (renderer part)

Source/devtools/front_end/InspectorFrontendHostStub.js

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 156 matching lines @@
 
     removeFileSystem: function(fileSystemPath)
     {
     },
 
     isolatedFileSystem: function(fileSystemId, registeredName)
     {
         return null;
     },
 
+    upgradeDraggedFileSystemPermissions: function(domFileSystem)
+    {
+    },
+
     indexPath: function(requestId, fileSystemPath)
     {
     },
 
     stopIndexing: function(requestId)
     {
     },
 
     searchInPath: function(requestId, fileSystemPath, query)
     {
@@ skipping 66 matching lines @@
     p.addStyleClass("help-section");
     p.createChild("span").textContent = "Remote debugging has been terminated with reason: ";
     p.createChild("span", "error-message").textContent = reason;
     p.createChild("br");
     p.createChild("span").textContent = "Please re-attach to the new target.";
 }
 
 WebInspector.RemoteDebuggingTerminatedScreen.prototype = {
     __proto__: WebInspector.HelpScreen.prototype
 }