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

ui/gfx/canvas_android.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/canvas.h"
 
 #include "base/logging.h"
 #include "ui/gfx/font.h"
 
 namespace gfx {
 
 // static
-void Canvas::SizeStringInt(const string16& text,
+void Canvas::SizeStringInt(const base::string16& text,
                            const gfx::Font& font,
                            int* width,
                            int* height,
                            int line_height,
                            int flags) {
   NOTIMPLEMENTED();
 }
 
-void Canvas::DrawStringWithShadows(const string16& text,
+void Canvas::DrawStringWithShadows(const base::string16& text,
                                    const gfx::Font& font,
                                    SkColor color,
                                    const gfx::Rect& text_bounds,
                                    int line_height,
                                    int flags,
                                    const ShadowValues& shadows) {
   NOTIMPLEMENTED();
 }
 
 }  // namespace gfx