Replace direct access to kGoogleServicesUsername with calls to SigninManager.

chrome/test/data/webui/ntp4_browsertest.cc

Index: chrome/test/data/webui/ntp4_browsertest.cc
diff --git a/chrome/test/data/webui/ntp4_browsertest.cc b/chrome/test/data/webui/ntp4_browsertest.cc
index 2f6fc87ecd072bdfaa21839168834a8dc0d1b0af..7c292aba6571f119c3cdb60aa8388b5acc5d82b3 100644
--- a/chrome/test/data/webui/ntp4_browsertest.cc
+++ b/chrome/test/data/webui/ntp4_browsertest.cc
@@ -6,14 +6,16 @@
 
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/pref_names.h"
+#include "components/signin/core/browser/signin_manager.h"
 
 NTP4LoggedInWebUITest::NTP4LoggedInWebUITest() {}
 
 NTP4LoggedInWebUITest::~NTP4LoggedInWebUITest() {}
 
 void NTP4LoggedInWebUITest::SetLoginName(const std::string& name) {
-  browser()->profile()->GetPrefs()->SetString(prefs::kGoogleServicesUsername,
-                                              name);
+  SigninManagerFactory::GetForProfile(browser()->profile())->
+      SetAuthenticatedUsername(name);
 }