[NOT FOR REVIEW] Instrument net/ with trace events.

net/spdy/spdy_session.cc

Index: net/spdy/spdy_session.cc
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index 0cff0ebcb6f43eafe848e5881c86dab51ec91f90..d8973a1df12dfd34b48aed9c8fde19b04b26017a 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -50,6 +50,8 @@
 #include "net/ssl/ssl_cipher_suite_names.h"
 #include "net/ssl/ssl_connection_status_flags.h"
 
+#include "base/trace_event/trace_event.h"
+
 namespace net {
 
 namespace {
@@ -1392,6 +1394,7 @@ void SpdySession::EnqueueResetStreamFrame(SpdyStreamId stream_id,
 }
 
 void SpdySession::PumpReadLoop(ReadState expected_read_state, int result) {
+  TRACE_EVENT0("net", "net::SpdySession::PumpReadLoop");
   // TODO(bnc): Remove ScopedTracker below once crbug.com/462774 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION("462774 SpdySession::PumpReadLoop"));