Pass WebKit priority changes and parsing messages up to the browser process.

content/public/browser/resource_throttle.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_H_
 #define CONTENT_PUBLIC_BROWSER_RESOURCE_THROTTLE_H_
 
 #include <vector>
 
 class GURL;
 
 namespace content {
 
 class ResourceController;
 
 // A ResourceThrottle gets notified at various points during the process of
 // loading a resource.  At each stage, it has the opportunity to defer the
 // resource load.  The ResourceController interface may be used to resume a
 // deferred resource load, or it may be used to cancel a resource load at any
 // time.
 class ResourceThrottle {
  public:
   virtual ~ResourceThrottle() {}
 
   virtual void WillStartRequest(bool* defer) {}
   virtual void WillRedirectRequest(const GURL& new_url, bool* defer) {}
   virtual void WillProcessResponse(bool* defer) {}
+  virtual void OnRequestPriorityChanged() {}

[darin (slow to review), 2013/02/06 05:04:13]

Hmm, this doesn't quite fit with the scope of ResourceThrottle.  All of the
other methods are about providing opportunities to defer resource loading at
particular stages of the process.

 
   void set_controller_for_testing(ResourceController* c) {
     controller_ = c;
   }
 
  protected:
   ResourceThrottle() : controller_(NULL) {}
   ResourceController* controller() { return controller_; }
 
  private:
   friend class ThrottlingResourceHandler;
   void set_controller(ResourceController* c) { controller_ = c; }
 
   ResourceController* controller_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RESOURCE_THROTTLE_H_