Adding instrumentation to locate the source of jankiness.

google_apis/gaia/gaia_oauth_client.cc

Index: google_apis/gaia/gaia_oauth_client.cc
diff --git a/google_apis/gaia/gaia_oauth_client.cc b/google_apis/gaia/gaia_oauth_client.cc
index b6c0d2e8a49bf4ffe088f325305d35a840542496..8f2565e3835bfb696e588227c38a99e4953f6f0c 100644
--- a/google_apis/gaia/gaia_oauth_client.cc
+++ b/google_apis/gaia/gaia_oauth_client.cc
@@ -7,6 +7,7 @@
 #include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/profiler/scoped_profile.h"
 #include "base/strings/string_util.h"
 #include "base/values.h"
 #include "google_apis/gaia/gaia_urls.h"
@@ -226,6 +227,11 @@ void GaiaOAuthClient::Core::MakeGaiaRequest(
 // URLFetcher::Delegate implementation.
 void GaiaOAuthClient::Core::OnURLFetchComplete(
     const net::URLFetcher* source) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422577 GaiaOAuthClient::Core::OnURLFetchComplete"));
+
   bool should_retry = false;
   HandleResponse(source, &should_retry);
   if (should_retry) {