[Cleanup] Remove StringPrintf from global namespace

chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc

Index: chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc
diff --git a/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc b/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc
index e1173e026cc9167632bd0247447e80cf29035cc2..8351cc790716e01cb383113cc5e154876ef67207 100644
--- a/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc
+++ b/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc
@@ -46,12 +46,11 @@ class SetInputMethodListener : public content::NotificationObserver {
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE {
     const std::string& content = *content::Details<std::string>(details).ptr();
-    const std::string expected_message = StringPrintf("%s:%s",
-                                                      kSetInputMethodMessage,
-                                                      kNewInputMethod);
+    const std::string expected_message =
+        base::StringPrintf("%s:%s", kSetInputMethodMessage, kNewInputMethod);
     if (content == expected_message) {
       chromeos::input_method::GetInputMethodManager()->
-          ChangeInputMethod(StringPrintf("xkb:%s", kNewInputMethod));
+          ChangeInputMethod(base::StringPrintf("xkb:%s", kNewInputMethod));
 
       extensions::TestSendMessageFunction* function =
           content::Source<extensions::TestSendMessageFunction>(