Adding instrumentation to locate the source of jankiness.

components/autofill/core/browser/autocomplete_history_manager.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/autofill/core/browser/autocomplete_history_manager.h"
 
 #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"
 #include "components/autofill/core/browser/autofill_driver.h"
 #include "components/autofill/core/browser/autofill_external_delegate.h"
 #include "components/autofill/core/browser/validation.h"
 #include "components/autofill/core/common/autofill_pref_names.h"
 #include "components/autofill/core/common/form_data.h"
 
 namespace autofill {
@@ skipping 26 matching lines @@
   DCHECK(autofill_client_);
 }
 
 AutocompleteHistoryManager::~AutocompleteHistoryManager() {
   CancelPendingQuery();
 }
 
 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;
 
   if (!autofill_client_->IsAutocompleteEnabled()) {
     SendSuggestions(NULL);
     return;
   }
 
   DCHECK(result);
   // Returning early here if |result| is NULL.  We've seen this happen on
@@ skipping 122 matching lines @@
                                             autofill_unique_ids_);
 
   query_id_ = 0;
   autofill_values_.clear();
   autofill_labels_.clear();
   autofill_icons_.clear();
   autofill_unique_ids_.clear();
 }
 
 }  // namespace autofill