Adding instrumentation to locate the source of jankiness.

chrome/browser/safe_browsing/protocol_manager.cc

Index: chrome/browser/safe_browsing/protocol_manager.cc
diff --git a/chrome/browser/safe_browsing/protocol_manager.cc b/chrome/browser/safe_browsing/protocol_manager.cc
index 29bc28a2c5dc2564f1b1d1eff01393e53637486c..64dc05be8346456ca305aa48f50931fd38aa8a31 100644
--- a/chrome/browser/safe_browsing/protocol_manager.cc
+++ b/chrome/browser/safe_browsing/protocol_manager.cc
@@ -8,6 +8,7 @@
 #include "base/logging.h"
 #include "base/memory/scoped_vector.h"
 #include "base/metrics/histogram.h"
+#include "base/profiler/scoped_profile.h"
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
@@ -226,6 +227,11 @@ void SafeBrowsingProtocolManager::GetNextUpdate() {
 //              required, the SafeBrowsing servers will tell us to get it again.
 void SafeBrowsingProtocolManager::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 SafeBrowsingProtocolManager::OnURLFetchComplete"));
+
   DCHECK(CalledOnValidThread());
   scoped_ptr<const net::URLFetcher> fetcher;