Use a direct include of the message_loop header in content/, part 3.

content/browser/web_contents/web_drag_dest_gtk.cc

 // 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.
 
 #include "content/browser/web_contents/web_drag_dest_gtk.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
-#include "base/message_loop.h"
+#include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/web_contents/drag_utils_gtk.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/browser/web_drag_dest_delegate.h"
 #include "content/public/common/url_constants.h"
 #include "net/base/net_util.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
 #include "ui/base/clipboard/custom_data_helper.h"
@@ skipping 307 matching lines @@
   gtk_drag_finish(context, is_drop_target_, FALSE, time);
 
   return TRUE;
 }
 
 RenderViewHostImpl* WebDragDestGtk::GetRenderViewHost() const {
   return static_cast<RenderViewHostImpl*>(web_contents_->GetRenderViewHost());
 }
 
 }  // namespace content