Uses and returns the fractional width in text eliding

ui/gfx/font_list.h

Index: ui/gfx/font_list.h
diff --git a/ui/gfx/font_list.h b/ui/gfx/font_list.h
index 2c47f4ca1a479b9d78f66c6c2a4c5ea09e20d948..d2508f9f3ed708d9c0cf92360ff554e7649b6b95 100644
--- a/ui/gfx/font_list.h
+++ b/ui/gfx/font_list.h
@@ -88,6 +88,10 @@ class GFX_EXPORT FontList {
   // Returns the number of horizontal pixels needed to display |text|.
   int GetStringWidth(const base::string16& text) const;
 
+  // Returns the pixel width needed to display |text|. Note that the fractional
+  // width might be returned in some platforms.
+  float GetStringWidthF(const base::string16& text) const;
+
   // Returns the expected number of horizontal pixels needed to display the
   // specified length of characters. Call GetStringWidth() to retrieve the
   // actual number.