Server push cancellation: add NetLogs to track cache lookup transaction

net/log/net_log_event_type_list.h

Index: net/log/net_log_event_type_list.h
diff --git a/net/log/net_log_event_type_list.h b/net/log/net_log_event_type_list.h
index bfdc0945062aa2c0b5477ed72ecaf358b175a18c..5b0ed678c6d53816e9cefd767f20574791bbda5f 100644
--- a/net/log/net_log_event_type_list.h
+++ b/net/log/net_log_event_type_list.h
@@ -1303,6 +1303,24 @@ EVENT_TYPE(BIDIRECTIONAL_STREAM_READY)
 EVENT_TYPE(BIDIRECTIONAL_STREAM_FAILED)
 
 // ------------------------------------------------------------------------
+// SERVER_PUSH_LOOKUP_TRANSACTION
+// ------------------------------------------------------------------------
+
+// The start/end of a push lookup transaction for server push.

[eroman, 2017/02/07 22:33:42]

Per comments in the .cc, I think there is an opportunity to re-structure this so
that the begin/end cache lookup is within a single event [BEGIN] and [END].

Otherwise I am not sure how useful the [END] phase of this event is, given that
it measures something different from the [BEGIN].

+//   {
+//     "source_dependency": <Source identifier for the server push lookp.
+//                           It can be a QUIC_SESSION or a HTTP2_SESSION>,
+//     "pushed_url": <The url that has been pushed and looked up>,
+//   }
+EVENT_TYPE(SERVER_PUSH_LOOKUP_TRANSACTION)
+
+// Logs the result of the push lookup transaction when it completes.
+//   {
+//     "found_in_cache": <True if the pushed url is found in cache>,
+//   }
+EVENT_TYPE(SERVER_PUSH_LOOKUP_COMPLETE)
+
+// ------------------------------------------------------------------------
 // SpdySession
 // ------------------------------------------------------------------------