[Prerender] Restore request priorities when swapped in

chrome/browser/prerender/prerender_resource_throttle.h

Index: chrome/browser/prerender/prerender_resource_throttle.h
diff --git a/chrome/browser/prerender/prerender_resource_throttle.h b/chrome/browser/prerender/prerender_resource_throttle.h
index a9f853ec9ccb45379d74940b614b10688629d6d5..a9fa3e039beb770dd115ea8a5c5227f08aa9ce2e 100644
--- a/chrome/browser/prerender/prerender_resource_throttle.h
+++ b/chrome/browser/prerender/prerender_resource_throttle.h
@@ -14,6 +14,7 @@
 #include "content/public/browser/resource_request_info.h"
 #include "content/public/browser/resource_throttle.h"
 #include "content/public/common/resource_type.h"
+#include "net/base/request_priority.h"
 
 class GURL;
 
@@ -50,6 +51,9 @@ class PrerenderResourceThrottle
   // May only be called if currently throttling the resource.
   void ResumeHandler();
 
+  // Resets the resource priority back to its original value.
+  void ResetResourcePriority();
+
   static void OverridePrerenderContentsForTesting(PrerenderContents* contents);
 
  private:
@@ -89,6 +93,10 @@ class PrerenderResourceThrottle
 
   net::URLRequest* request_;
   int load_flags_;  // Load flags to be OR'ed with the existing request flags.

[Charlie Harrison, 2017/04/12 12:37:26]

nit: newline below.

[droger, 2017/04/12 13:20:54]

Done.

+  // The throttle changes most request priorities to IDLE during prerendering.
+  // The priority is reset back to the original priority when prerendering is
+  // finished, unless the original priority is IDLE.
+  net::RequestPriority original_request_priority_;
 
   scoped_refptr<PrerenderThrottleInfo> prerender_throttle_info_;