Adding instrumentation to locate the source of jankiness.

components/translate/core/browser/translate_url_fetcher.cc

Index: components/translate/core/browser/translate_url_fetcher.cc
diff --git a/components/translate/core/browser/translate_url_fetcher.cc b/components/translate/core/browser/translate_url_fetcher.cc
index 09704fd9171498199afdb450ef520850693bdd0b..3505ddb15216c2ab24a69761b39e1d4514e3804b 100644
--- a/components/translate/core/browser/translate_url_fetcher.cc
+++ b/components/translate/core/browser/translate_url_fetcher.cc
@@ -4,6 +4,7 @@
 
 #include "components/translate/core/browser/translate_url_fetcher.h"
 
+#include "base/profiler/scoped_profile.h"
 #include "components/translate/core/browser/translate_download_manager.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_status_code.h"
@@ -67,6 +68,11 @@ bool TranslateURLFetcher::Request(
 }
 
 void TranslateURLFetcher::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 TranslateURLFetcher::OnURLFetchComplete"));
+
   DCHECK(fetcher_.get() == source);
 
   std::string data;