chrome: Cleanup class/struct forward declarations

chrome/browser/android/download/download_controller.h

 // Copyright 2016 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.
 
 // This class pairs with DownloadController on Java side to forward requests
 // for GET downloads to the current DownloadListener. POST downloads are
 // handled on the native side.
 //
 // Both classes are Singleton classes. C++ object owns Java object.
 //
 // Call sequence
 // GET downloads:
 // DownloadController::CreateGETDownload() =>
 // DownloadController.newHttpGetDownload() =>
 // DownloadListener.onDownloadStart() /
 // DownloadListener2.requestHttpGetDownload()
 //
 
 #ifndef CHROME_BROWSER_ANDROID_DOWNLOAD_DOWNLOAD_CONTROLLER_H_
 #define CHROME_BROWSER_ANDROID_DOWNLOAD_DOWNLOAD_CONTROLLER_H_
 
 #include "base/android/scoped_java_ref.h"
 #include "base/memory/singleton.h"
 #include "chrome/browser/android/download/download_controller_base.h"
 
-namespace net {
-class URLRequest;
-}
-
 namespace ui {
 class WindowAndroid;
 }
 
 namespace content {
 class WebContents;
 }
 
 class DownloadController : public DownloadControllerBase {
  public:
@@ skipping 55 matching lines @@
   JavaObject* GetJavaObject();
 
   JavaObject* java_object_;
 
   std::string default_file_name_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadController);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_DOWNLOAD_DOWNLOAD_CONTROLLER_H_