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

chrome/browser/ui/cocoa/profile_signin_confirmation_view_controller_browsertest.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/profile_signin_confirmation_view_controller.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 147 matching lines @@
 
 IN_PROC_BROWSER_TEST_F(ProfileSigninConfirmationViewControllerTest,
                        DoNotOfferNewProfile) {
   SetupDialog(/*offerProfileCreation = */ false);
   // Create Profile button shouldn't exist.
   EXPECT_NSEQ(nil, [controller_ createProfileButton]);
   // Explanation shouldn't mention creating a new profile.
   NSString* explanationWithoutCreateProfile = base::SysUTF16ToNSString(
       l10n_util::GetStringFUTF16(
           IDS_ENTERPRISE_SIGNIN_EXPLANATION_WITHOUT_PROFILE_CREATION_NEW_STYLE,
-          UTF8ToUTF16(username()), learn_more()));
+          base::UTF8ToUTF16(username()), learn_more()));
   EXPECT_NSEQ(explanationWithoutCreateProfile,
               [[[controller_ explanationField] textStorage] string]);
 }
 
 IN_PROC_BROWSER_TEST_F(ProfileSigninConfirmationViewControllerTest,
                        OfferNewProfile) {
   SetupDialog(/*offerProfileCreation = */ true);
   // Create Profile button should exist and be visible.
   EXPECT_NSNE(nil, [controller_ createProfileButton]);
   EXPECT_TRUE([[[controller_ view] subviews]
                 containsObject:[controller_ createProfileButton]]);
   NSString* explanationWithCreateProfile = base::SysUTF16ToNSString(
       l10n_util::GetStringFUTF16(
           IDS_ENTERPRISE_SIGNIN_EXPLANATION_WITH_PROFILE_CREATION_NEW_STYLE,
-          UTF8ToUTF16(username()), learn_more()));
+          base::UTF8ToUTF16(username()), learn_more()));
   EXPECT_NSEQ(explanationWithCreateProfile,
               [[[controller_ explanationField] textStorage] string]);
 }