Add a ResourceScheduler to ResourceDispatcherHost.

content/common/resource_dispatcher.h

Index: content/common/resource_dispatcher.h
diff --git a/content/common/resource_dispatcher.h b/content/common/resource_dispatcher.h
index 509a2661528647f59f74dcd00e1c5af8689dd991..141e89c188c4b102c01f4a61bdfbbdc6dd43c288 100644
--- a/content/common/resource_dispatcher.h
+++ b/content/common/resource_dispatcher.h
@@ -61,6 +61,10 @@ class CONTENT_EXPORT ResourceDispatcher : public IPC::Listener {
   // Toggles the is_deferred attribute for the specified request.
   void SetDefersLoading(int request_id, bool value);
 
+  // Indicates the priority of the specified request changed.
+  void DidChangePriority(int routing_id, int request_id,
+                         net::RequestPriority new_priority);
+
   // This does not take ownership of the delegate. It is expected that the
   // delegate have a longer lifetime than the ResourceDispatcher.
   void set_delegate(ResourceDispatcherDelegate* delegate) {