[Prerender] Restore request priorities when swapped in

chrome/browser/prerender/prerender_contents.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 CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 217 matching lines @@
 
   // Marks prerender as used and releases any throttled resource requests.
   void PrepareForUse();
 
   // Called when a PrerenderResourceThrottle defers a request. If the prerender
   // is used it'll be resumed on the IO thread, otherwise they will get
   // cancelled automatically if prerendering is cancelled.
   void AddResourceThrottle(
       const base::WeakPtr<PrerenderResourceThrottle>& throttle);
 
+  // Called when a PrerenderResourceThrottle changes a resource priority to
+  // net::IDLE. The resources are reset back to their original priorities when
+  // the prerender contents is swapped in.
+  void AddIdleResource(
+      const base::WeakPtr<PrerenderResourceThrottle>& throttle);
+
   // Increments the number of bytes fetched over the network for this prerender.
   void AddNetworkBytes(int64_t bytes);
 
   bool prerendering_has_been_cancelled() const {
     return prerendering_has_been_cancelled_;
   }
 
   // Running byte count. Increased when each resource completes loading.
   int64_t network_bytes() { return network_bytes_; }
 
@@ skipping 117 matching lines @@
   gfx::Rect bounds_;
 
   typedef std::vector<history::HistoryAddPageArgs> AddPageVector;
 
   // Caches pages to be added to the history.
   AddPageVector add_page_vector_;
 
   // Resources that are throttled, pending a prerender use. Can only access a
   // throttle on the IO thread.
   std::vector<base::WeakPtr<PrerenderResourceThrottle> > resource_throttles_;
+  // Resources for which the priority was lowered to net::IDLE.
+  std::vector<base::WeakPtr<PrerenderResourceThrottle>> idle_resources_;
 
   // A running tally of the number of bytes this prerender has caused to be
   // transferred over the network for resources.  Updated with AddNetworkBytes.
   int64_t network_bytes_;
 
   base::WeakPtrFactory<PrerenderContents> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderContents);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_CONTENTS_H_