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

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_view_unittest.mm

 // Copyright (c) 2012 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.
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/bookmarks/bookmark_test_helpers.h"
@@ skipping 108 matching lines @@
     [[[mock_controller stub] andReturnValue:OCMOCK_VALUE(model)] bookmarkModel];
     return [mock_controller retain];
   }
 
   id GetMockButton(id mock_controller) {
     BookmarkModel* bookmark_model =
         BookmarkModelFactory::GetForProfile(profile());
     const BookmarkNode* node =
         bookmark_model->AddURL(bookmark_model->bookmark_bar_node(),
                                0,
-                               ASCIIToUTF16("Test Bookmark"),
+                               base::ASCIIToUTF16("Test Bookmark"),
                                GURL("http://www.exmaple.com"));
 
     id mock_button = [OCMockObject mockForClass:[BookmarkButton class]];
     [[[mock_button stub] andReturnValue:OCMOCK_VALUE(node)] bookmarkNode];
     return [mock_button retain];
   }
 
   base::scoped_nsobject<id> mock_controller_;
   base::scoped_nsobject<BookmarkBarFolderView> view_;
   base::scoped_nsobject<id> mock_button_;
@@ skipping 63 matching lines @@
   mock_controller_.reset(GetMockController(
       NO, BookmarkModelFactory::GetForProfile(profile())));
   [view_ setController:mock_controller_];
   [[[mock_controller_ expect] andReturnUnsignedInteger:NSDragOperationNone]
    draggingEntered:drag_info];
   EXPECT_EQ([view_ draggingEntered:drag_info], NSDragOperationMove);
   EXPECT_FALSE([view_ dropIndicatorShown]);
 }
 
 }  // namespace