Add TRACE_EVENT macros to net.

net/socket/client_socket_handle.cc

Index: net/socket/client_socket_handle.cc
diff --git a/net/socket/client_socket_handle.cc b/net/socket/client_socket_handle.cc
index b177fb6f3b2fa4486e8901f221db8741e70740d4..97b1b89d8445801ca498634872c3d080f4baeba7 100644
--- a/net/socket/client_socket_handle.cc
+++ b/net/socket/client_socket_handle.cc
@@ -10,6 +10,7 @@
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
+#include "base/trace_event/trace_event.h"
 #include "net/base/net_errors.h"
 #include "net/socket/client_socket_pool.h"
 
@@ -140,6 +141,7 @@ void ClientSocketHandle::SetSocket(scoped_ptr<StreamSocket> s) {
 }
 
 void ClientSocketHandle::OnIOComplete(int result) {
+  TRACE_EVENT0("net", "ClientSocketHandle::OnIOComplete");
   CompletionCallback callback = user_callback_;
   user_callback_.Reset();
   HandleInitCompletion(result);