Remove 'using base::string16;' from base/strings/string16.h and remove temporary

ui/message_center/cocoa/notification_controller.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 "ui/message_center/cocoa/notification_controller.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 209 matching lines @@
 
 // Gets the rectangle in which notification content should be placed. This
 // rectangle is to the right of the icon and left of the control buttons.
 // This depends on the icon_ and closeButton_ being initialized.
 - (NSRect)currentContentRect;
 
 // Returns the wrapped text that could fit within the content rect with not
 // more than the given number of lines. The wrapped text would be painted using
 // the given font. The Ellipsis could be added at the end of the last line if
 // it is too long.
-- (string16)wrapText:(const base::string16&)text
-             forFont:(NSFont*)font
+- (base::string16)wrapText:(const base::string16&)text
+                   forFont:(NSFont*)font
     maxNumberOfLines:(size_t)lines;
 @end
 
 ////////////////////////////////////////////////////////////////////////////////
 
 @implementation MCNotificationController
 
 - (id)initWithNotification:(const message_center::Notification*)notification
     messageCenter:(message_center::MessageCenter*)messageCenter {
   if ((self = [super initWithNibName:nil bundle:nil])) {
@@ skipping 475 matching lines @@
   DCHECK(closeButton_);
 
   NSRect iconFrame, contentFrame;
   NSDivideRect([[self view] bounds], &iconFrame, &contentFrame,
       NSWidth([icon_ frame]) + message_center::kIconToTextPadding,
       NSMinXEdge);
   contentFrame.size.width -= NSWidth([closeButton_ frame]);
   return contentFrame;
 }
 
-- (string16)wrapText:(const base::string16&)text
-             forFont:(NSFont*)nsfont
+- (base::string16)wrapText:(const base::string16&)text
+                   forFont:(NSFont*)nsfont
     maxNumberOfLines:(size_t)lines {
   if (text.empty())
     return text;
   gfx::FontList font_list((gfx::Font(nsfont)));
   int width = NSWidth([self currentContentRect]);
   int height = (lines + 1) * font_list.GetHeight();
 
   std::vector<base::string16> wrapped;
   gfx::ElideRectangleText(text, font_list, width, height,
                           gfx::WRAP_LONG_WORDS, &wrapped);
@@ skipping 10 matching lines @@
     if (gfx::GetStringWidth(last, font_list) > width)
       last = gfx::ElideText(last, font_list, width, gfx::ELIDE_AT_END);
     wrapped.resize(lines - 1);
     wrapped.push_back(last);
   }
 
   return lines == 1 ? wrapped[0] : JoinString(wrapped, '\n');
 }
 
 @end