Font fallback for UI

ui/gfx/platform_font_win.h

Index: ui/gfx/platform_font_win.h
diff --git a/ui/gfx/platform_font_win.h b/ui/gfx/platform_font_win.h
index 1cb0c9992f25b385fd9698680017c65e2aa2f07d..e5aa9bc79d3b2abe7ca7463803ec20618c75c829 100644
--- a/ui/gfx/platform_font_win.h
+++ b/ui/gfx/platform_font_win.h
@@ -15,6 +15,7 @@
 #include "ui/gfx/platform_font.h"
 
 struct IDWriteFactory;
+struct IDWriteFont;
 
 namespace gfx {
 
@@ -204,6 +205,12 @@ class GFX_EXPORT PlatformFontWin : public PlatformFont {
   DISALLOW_COPY_AND_ASSIGN(PlatformFontWin);
 };
 
+// Returns the family name for the |IDWriteFont| interface passed in.
+// The family name is returned in the |family_name| parameter.
+// Returns S_OK on success.
+HRESULT GetFamilyNameFromDirectWriteFont(IDWriteFont* dwrite_font,
+                                         base::string16* family_name);
+
 }  // namespace gfx
 
 #endif  // UI_GFX_PLATFORM_FONT_WIN_H_