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

chrome/browser/ui/cocoa/autofill/autofill_notification_controller_unittest.mm

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/autofill/autofill_notification_controller.h"
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/autofill/autofill_dialog_types.h"
 #include "testing/gtest_mac.h"
 #import "ui/base/test/ui_cocoa_test_helper.h"
 
+using base::ASCIIToUTF16;
+
 namespace {
 
 class AutofillNotificationControllerTest : public ui::CocoaTest {
  public:
   virtual void SetUp() {
     CocoaTest::SetUp();
     InitControllerWithNotification(
         autofill::DialogNotification(autofill::DialogNotification::NONE,
                                      ASCIIToUTF16("A notification title")));
   }
@@ skipping 75 matching lines @@
           autofill::DialogNotification::WALLET_USAGE_CONFIRMATION,
           ASCIIToUTF16("A notification title"));
   ASSERT_TRUE(notification.HasCheckbox());
   notification.set_tooltip_text(ASCIIToUTF16("My very informative tooltip."));
   InitControllerWithNotification(notification);
 
   EXPECT_TRUE([[controller_ textview] isHidden]);
   EXPECT_FALSE([[controller_ checkbox] isHidden]);
   EXPECT_FALSE([[controller_ tooltipView] isHidden]);
 }