ui/gfx: Use base::string16 now that string16 was moved into base namespace.

ui/gfx/font.cc

 // 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 "ui/gfx/font.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/gfx/platform_font.h"
 
 namespace gfx {
@@ skipping 40 matching lines @@
 }
 
 int Font::GetBaseline() const {
   return platform_font_->GetBaseline();
 }
 
 int Font::GetAverageCharacterWidth() const {
   return platform_font_->GetAverageCharacterWidth();
 }
 
-int Font::GetStringWidth(const string16& text) const {
+int Font::GetStringWidth(const base::string16& text) const {
   return platform_font_->GetStringWidth(text);
 }
 
 int Font::GetExpectedTextWidth(int length) const {
   return platform_font_->GetExpectedTextWidth(length);
 }
 
 int Font::GetStyle() const {
   return platform_font_->GetStyle();
 }
 
 std::string Font::GetFontName() const {
   return platform_font_->GetFontName();
 }
 
 int Font::GetFontSize() const {
   return platform_font_->GetFontSize();
 }
 
 NativeFont Font::GetNativeFont() const {
   return platform_font_->GetNativeFont();
 }
 
 }  // namespace gfx