Adding instrumentation to locate the source of jankiness.

components/autofill/core/browser/autocomplete_history_manager.cc

Index: components/autofill/core/browser/autocomplete_history_manager.cc
diff --git a/components/autofill/core/browser/autocomplete_history_manager.cc b/components/autofill/core/browser/autocomplete_history_manager.cc
index ccd4b5e44c8140f527963d18534a8be204733627..d96249b47902241b13def2ddd8f7b9d01ca9b970 100644
--- a/components/autofill/core/browser/autocomplete_history_manager.cc
+++ b/components/autofill/core/browser/autocomplete_history_manager.cc
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "base/prefs/pref_service.h"
+#include "base/profiler/scoped_profile.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/autofill/core/browser/autofill_client.h"
@@ -53,6 +54,11 @@ AutocompleteHistoryManager::~AutocompleteHistoryManager() {
 void AutocompleteHistoryManager::OnWebDataServiceRequestDone(
     WebDataServiceBase::Handle h,
     const WDTypedResult* result) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422460 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422460 AutocompleteHistoryManager::OnWebDataServiceRequestDone"));
+
   DCHECK(pending_query_handle_);
   pending_query_handle_ = 0;