Use filter context to track stats better in SDCH filtering

net/url_request/url_request_job_metrics.cc

Index: net/url_request/url_request_job_metrics.cc
===================================================================
--- net/url_request/url_request_job_metrics.cc	(revision 11636)
+++ net/url_request/url_request_job_metrics.cc	(working copy)
@@ -23,8 +23,9 @@
 
   TimeDelta elapsed = end_time_ - start_time_;
   StringAppendF(text,
-      L"; total bytes read = %d; read calls = %d; time = %lld ms;",
-      total_bytes_read_, number_of_read_IO_, elapsed.InMilliseconds());
+      L"; total bytes read = %ld; read calls = %d; time = %lld ms;",
+      static_cast<long>(total_bytes_read_),
+      number_of_read_IO_, elapsed.InMilliseconds());
 
   if (success_) {
     text->append(L" success.");