Log the QUIC priority when sending requests.

net/base/net_log_event_type_list.h

Index: net/base/net_log_event_type_list.h
diff --git a/net/base/net_log_event_type_list.h b/net/base/net_log_event_type_list.h
index ca43b1bf12c2649e51cf2c2542d3ffa5c8ae831a..7ebe01cc4e6fc2a0d2f90a099300bdec16828915 100644
--- a/net/base/net_log_event_type_list.h
+++ b/net/base/net_log_event_type_list.h
@@ -989,6 +989,14 @@ EVENT_TYPE(HTTP_TRANSACTION_SEND_REQUEST_BODY)
 //   }
 EVENT_TYPE(HTTP_TRANSACTION_SPDY_SEND_REQUEST_HEADERS)
 
+// This event is sent for a HTTP request over a SPDY stream.
+// The following parameters are attached:
+//   {
+//     "headers": <The list of header:value pairs>,
+//     "quic_priority": <Integer representing the priority of this request>,
+//   }
+EVENT_TYPE(HTTP_TRANSACTION_QUIC_SEND_REQUEST_HEADERS)
+
 // Measures the time to read HTTP response headers from the server.
 EVENT_TYPE(HTTP_TRANSACTION_READ_HEADERS)