Adding instrumentation to locate the source of jankiness.

google_apis/gcm/engine/connection_factory_impl.cc

Index: google_apis/gcm/engine/connection_factory_impl.cc
diff --git a/google_apis/gcm/engine/connection_factory_impl.cc b/google_apis/gcm/engine/connection_factory_impl.cc
index 218f833d7c689a5d53b9306dec97d385ebac88b7..a8ec37fe5604fd0052a318def9afbbbaf2b6ced1 100644
--- a/google_apis/gcm/engine/connection_factory_impl.cc
+++ b/google_apis/gcm/engine/connection_factory_impl.cc
@@ -7,6 +7,7 @@
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
+#include "base/profiler/scoped_tracker.h"
 #include "google_apis/gcm/engine/connection_handler_impl.h"
 #include "google_apis/gcm/monitoring/gcm_stats_recorder.h"
 #include "google_apis/gcm/protocol/mcs.pb.h"
@@ -342,6 +343,10 @@ base::TimeTicks ConnectionFactoryImpl::NowTicks() {
 }
 
 void ConnectionFactoryImpl::OnConnectDone(int result) {
+  // TODO(pkasting): Remove ScopedTracker below once crbug.com/455884 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "455884 ConnectionFactoryImpl::OnConnectDone"));
   if (result != net::OK) {
     // If the connection fails, try another proxy.
     result = ReconsiderProxyAfterError(result);