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

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

 // Copyright (c) 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_account_chooser.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/autofill/mock_autofill_dialog_view_delegate.h"
@@ skipping 64 matching lines @@
   EXPECT_TRUE(hasIcon);
   EXPECT_TRUE(hasLink);
   EXPECT_TRUE(hasPopup);
 }
 
 // Validate that the account menu is properly populated.
 TEST_F(AutofillAccountChooserTest, PopulatesMenu) {
   using namespace testing;
   MenuDelegate delegate;
   ui::SimpleMenuModel model(&delegate);
-  model.AddItem(1, ASCIIToUTF16("one"));
-  model.AddItem(2, ASCIIToUTF16("two"));
+  model.AddItem(1, base::ASCIIToUTF16("one"));
+  model.AddItem(2, base::ASCIIToUTF16("two"));
 
   EXPECT_CALL(delegate_, MenuModelForAccountChooser())
       .WillOnce(Return(&model));
   [view_ update];
 
   MenuButton* button = nil;
   for (id view in [view_ subviews]) {
     if ([view isKindOfClass:[MenuButton class]]) {
       button = view;
       break;
     }
   }
 
   NSArray* items = [[button attachedMenu] itemArray];
   EXPECT_EQ(3U, [items count]);
   EXPECT_NSEQ(@"", [[items objectAtIndex:0] title]);
   EXPECT_NSEQ(@"one", [[items objectAtIndex:1] title]);
   EXPECT_NSEQ(@"two", [[items objectAtIndex:2] title]);
 }