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

ui/gfx/platform_font_pango.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/platform_font_pango.h"
 
 #include <fontconfig/fontconfig.h>
 #include <pango/pango.h>
 
 #include <algorithm>
@@ skipping 180 matching lines @@
 
 int PlatformFontPango::GetBaseline() const {
   return ascent_pixels_;
 }
 
 int PlatformFontPango::GetAverageCharacterWidth() const {
   const_cast<PlatformFontPango*>(this)->InitPangoMetrics();
   return SkScalarRound(average_width_pixels_);
 }
 
-int PlatformFontPango::GetStringWidth(const string16& text) const {
+int PlatformFontPango::GetStringWidth(const base::string16& text) const {
   return Canvas::GetStringWidth(text,
                                 Font(const_cast<PlatformFontPango*>(this)));
 }
 
 int PlatformFontPango::GetExpectedTextWidth(int length) const {
   double char_width = const_cast<PlatformFontPango*>(this)->GetAverageWidth();
   return round(static_cast<float>(length) * char_width);
 }
 
 int PlatformFontPango::GetStyle() const {
@@ skipping 172 matching lines @@
   return new PlatformFontPango(native_font);
 }
 
 // static
 PlatformFont* PlatformFont::CreateFromNameAndSize(const std::string& font_name,
                                                   int font_size) {
   return new PlatformFontPango(font_name, font_size);
 }
 
 }  // namespace gfx