Refactor the guts of ResourceDispatcherHostImpl into a new class named

content/public/browser/resource_throttle_controller.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_PUBLIC_BROWSER_RESOURCE_THROTTLE_CONTROLLER_H_
-#define CONTENT_PUBLIC_BROWSER_RESOURCE_THROTTLE_CONTROLLER_H_
-
-namespace content {
-
-// Used by ResourceThrottle implementations to either resume a deferred
-// resource load or cancel a resource load at any time.
-class ResourceThrottleController {
- public:
-  virtual void Cancel() = 0;
-  virtual void Resume() = 0;
- protected:
-  virtual ~ResourceThrottleController() {}
-};
-
-}  // namespace content
-
-#endif  // CONTENT_PUBLIC_BROWSER_RESOURCE_THROTTLE_CONTROLLER_H_