Remove unused ATL headers.

chrome/browser/tab_contents/web_drag_source.cc

 // Copyright (c) 2006-2008 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.
 
-#if defined(OS_WIN)
-#include <atlbase.h>
-#include <atlapp.h>
-#include <atlmisc.h>
-#endif
-
 #include "chrome/browser/tab_contents/web_drag_source.h"
 
 #include "chrome/browser/renderer_host/render_view_host.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/common/notification_type.h"
 #include "chrome/common/notification_service.h"
 
 using WebKit::WebDragOperationNone;
 using WebKit::WebDragOperationCopy;
 
@@ skipping 68 matching lines @@
     const NotificationSource& source, const NotificationDetails& details) {
   if (NotificationType::TAB_CONTENTS_SWAPPED == type) {
     // When the tab contents get swapped, our render view host goes away.
     // That's OK, we can continue the drag, we just can't send messages back to
     // our drag source.
     render_view_host_ = NULL;
   } else if (NotificationType::TAB_CONTENTS_DISCONNECTED) {
     NOTREACHED();
   }
 }