Enable touch-initiated drag-drop work on Windows

content/browser/web_contents/web_drag_source_win.h

 // 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.
 
 #ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_DRAG_SOURCE_WIN_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_DRAG_SOURCE_WIN_H_
 
 #include "base/basictypes.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
@@ skipping 21 matching lines @@
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   void set_effect(DWORD effect) { effect_ = effect; }
 
  protected:
   // ui::DragSourceWin
   virtual void OnDragSourceCancel();
   virtual void OnDragSourceDrop();
   virtual void OnDragSourceMove();
+  virtual bool ShouldDropDragSource(BOOL escape_pressed, DWORD key_state);
 
  private:
   // Cannot construct thusly.
   WebDragSource();
 
   // OnDragSourceDrop schedules its main work to be done after IDropTarget::Drop
   // by posting a task to this function.
   void DelayedOnDragSourceDrop();
 
+  void OnDragSourceEnded();
+
   // Keep a reference to the window so we can translate the cursor position.
   gfx::NativeWindow source_wnd_;
 
   // We use this as a channel to the renderer to tell it about various drag
   // drop events that it needs to know about (such as when a drag operation it
   // initiated terminates).
   RenderViewHost* render_view_host_;
 
   NotificationRegistrar registrar_;
 
   DWORD effect_;
 
   DISALLOW_COPY_AND_ASSIGN(WebDragSource);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_DRAG_SOURCE_WIN_H_