Change string16 to std::string in the gfx::Font() interface.

ui/gfx/font.cc

Index: ui/gfx/font.cc
diff --git a/ui/gfx/font.cc b/ui/gfx/font.cc
index 08b7b34e36c9a533950cb71723a909cb5f7700ec..1a3593fa76c6fff25b27c7eab7c334dce04c67ec 100644
--- a/ui/gfx/font.cc
+++ b/ui/gfx/font.cc
@@ -30,7 +30,7 @@ Font::Font(NativeFont native_font)
 Font::Font(PlatformFont* platform_font) : platform_font_(platform_font) {
 }
 
-Font::Font(const string16& font_name, int font_size)
+Font::Font(const std::string& font_name, int font_size)
     : platform_font_(PlatformFont::CreateFromNameAndSize(font_name,
                                                          font_size)) {
 }
@@ -70,7 +70,7 @@ int Font::GetStyle() const {
   return platform_font_->GetStyle();
 }
 
-string16 Font::GetFontName() const {
+std::string Font::GetFontName() const {
   return platform_font_->GetFontName();
 }