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

ui/gfx/platform_font.h

Index: ui/gfx/platform_font.h
diff --git a/ui/gfx/platform_font.h b/ui/gfx/platform_font.h
index 7e316fe78299b8d064fd9283b5ae033e8adee2d5..98b8f689f170319664c85afc87ce78ea468926d3 100644
--- a/ui/gfx/platform_font.h
+++ b/ui/gfx/platform_font.h
@@ -25,7 +25,7 @@ class UI_EXPORT PlatformFont : public base::RefCounted<PlatformFont> {
   static PlatformFont* CreateFromNativeFont(NativeFont native_font);
   // Creates a PlatformFont implementation with the specified |font_name| and
   // |font_size| in pixels.
-  static PlatformFont* CreateFromNameAndSize(const string16& font_name,
+  static PlatformFont* CreateFromNameAndSize(const std::string& font_name,
                                              int font_size);
 
   // Returns a new Font derived from the existing font.
@@ -60,7 +60,7 @@ class UI_EXPORT PlatformFont : public base::RefCounted<PlatformFont> {
   virtual int GetStyle() const = 0;
 
   // Returns the font name.
-  virtual string16 GetFontName() const = 0;
+  virtual std::string GetFontName() const = 0;
 
   // Returns the font size in pixels.
   virtual int GetFontSize() const = 0;