Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/accessibility/accessibility_extension_apitest.cc

Index: chrome/browser/accessibility/accessibility_extension_apitest.cc
diff --git a/chrome/browser/accessibility/accessibility_extension_apitest.cc b/chrome/browser/accessibility/accessibility_extension_apitest.cc
index 279e6d989c0154ded2e4d110b485bfe492ce4c61..00a1013b0f8c22c236259853e6ce1f9b9e9dddc1 100644
--- a/chrome/browser/accessibility/accessibility_extension_apitest.cc
+++ b/chrome/browser/accessibility/accessibility_extension_apitest.cc
@@ -35,7 +35,7 @@ IN_PROC_BROWSER_TEST_F(ExtensionApiTest, MAYBE_GetAlertsForTab) {
   const char kAlertMessage[] = "Simple Alert Infobar.";
   SimpleAlertInfoBarDelegate::Create(infobar_service,
                                      InfoBarDelegate::kNoIconID,
-                                     ASCIIToUTF16(kAlertMessage), false);
+                                     base::ASCIIToUTF16(kAlertMessage), false);
   CommandLine::ForCurrentProcess()->AppendSwitch(
       extensions::switches::kEnableExperimentalExtensionApis);
   ASSERT_TRUE(RunExtensionTest("accessibility/get_alerts_for_tab")) << message_;