Adding DRP specfic UMA for FirstContentfulPaint

content/browser/loader/resource_dispatcher_host_impl.h

Index: content/browser/loader/resource_dispatcher_host_impl.h
diff --git a/content/browser/loader/resource_dispatcher_host_impl.h b/content/browser/loader/resource_dispatcher_host_impl.h
index 6d5602b670e849d673fd181a4ad7e31bcd2d753f..6dc2489f44df270a4deec889a024b64b33515716 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.h
+++ b/content/browser/loader/resource_dispatcher_host_impl.h
@@ -358,21 +358,22 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
   // An init helper that runs on the IO thread.
   void OnInit();
 
   // A shutdown helper that runs on the IO thread.
   void OnShutdown();
 
   void OnRenderFrameDeleted(const GlobalFrameRoutingId& global_routing_id);
 
   // Helper function for regular and download requests.
   void BeginRequestInternal(scoped_ptr<net::URLRequest> request,
-                            scoped_ptr<ResourceHandler> handler);
+                            scoped_ptr<ResourceHandler> handler,
+                            ResourceContext* resource_context);
 
   void StartLoading(ResourceRequestInfoImpl* info,
                     scoped_ptr<ResourceLoader> loader);
 
   // We keep track of how much memory each request needs and how many requests
   // are issued by each renderer. These are known as OustandingRequestStats.
   // Memory limits apply to all requests sent to us by the renderers. There is a
   // limit for each renderer. File descriptor limits apply to requests that are
   // receiving their body. These are known as in-flight requests. There is a
   // global limit that applies for the browser process. Each render is allowed