content: Cleanup class/struct forward declarations

content/renderer/android/renderer_date_time_picker.h

 // 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.
 
 #ifndef CONTENT_RENDERER_ANDROID_RENDERER_DATE_TIME_PICKER_H_
 #define CONTENT_RENDERER_ANDROID_RENDERER_DATE_TIME_PICKER_H_
 
 #include "base/macros.h"
 #include "content/public/renderer/render_view_observer.h"
 #include "third_party/WebKit/public/web/WebDateTimeChooserParams.h"
 
-struct ViewHostMsg_DateTimeDialogValue_Params;
-
 namespace blink {
 class WebDateTimeChooserCompletion;
 }  // namespace blink
 
 namespace content {
 class RenderViewImpl;
 
 class RendererDateTimePicker : public RenderViewObserver {
  public:
   RendererDateTimePicker(
@@ skipping 14 matching lines @@
 
   blink::WebDateTimeChooserParams chooser_params_;
   blink::WebDateTimeChooserCompletion* chooser_completion_;  // Not owned by us
 
   DISALLOW_COPY_AND_ASSIGN(RendererDateTimePicker);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_ANDROID_RENDERER_DATE_TIME_PICKER_H_