Adding instrumentation to locate the source of jankiness.

components/translate/core/browser/translate_language_list.cc

Index: components/translate/core/browser/translate_language_list.cc
diff --git a/components/translate/core/browser/translate_language_list.cc b/components/translate/core/browser/translate_language_list.cc
index 6a9b8c2535eafeb08b0223ece23311f99a4ff813..5db1a1c701794980f5bbc5af7051877553255b37 100644
--- a/components/translate/core/browser/translate_language_list.cc
+++ b/components/translate/core/browser/translate_language_list.cc
@@ -256,12 +256,22 @@ void TranslateLanguageList::OnLanguageListFetchComplete(
 }
 
 void TranslateLanguageList::NotifyEvent(int line, const std::string& message) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
+  tracked_objects::ScopedProfile tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422577 TranslateLanguageList::NotifyEvent"));
+
   TranslateEventDetails details(__FILE__, line, message);
   callback_list_.Notify(details);
 }
 
 void TranslateLanguageList::SetSupportedLanguages(
     const std::string& language_list) {
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
+  tracked_objects::ScopedProfile tracking_profile1(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422577 TranslateLanguageList::SetSupportedLanguages 1"));
+
   // The format is:
   // sl({
   //   "sl": {"XX": "LanguageName", ...},
@@ -284,8 +294,20 @@ void TranslateLanguageList::SetSupportedLanguages(
   std::string languages_json = language_list.substr(
       kLanguageListCallbackNameLength,
       language_list.size() - kLanguageListCallbackNameLength - 1);
+
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
+  tracked_objects::ScopedProfile tracking_profile2(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422577 TranslateLanguageList::SetSupportedLanguages 2"));
+
   scoped_ptr<base::Value> json_value(
       base::JSONReader::Read(languages_json, base::JSON_ALLOW_TRAILING_COMMAS));
+
+  // TODO(vadimt): Remove ScopedProfile below once crbug.com/422577 is fixed.
+  tracked_objects::ScopedProfile tracking_profile3(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422577 TranslateLanguageList::SetSupportedLanguages 3"));
+
   if (json_value == NULL || !json_value->IsType(base::Value::TYPE_DICTIONARY)) {
     NOTREACHED();
     return;