Uses and returns the fractional width in text eliding

ui/gfx/font.h

Index: ui/gfx/font.h
diff --git a/ui/gfx/font.h b/ui/gfx/font.h
index 020ab64f744e1d807aaa404ddbf6bc046d218f3a..398eda363770b75a5d292a8170be4acbe2bc4408 100644
--- a/ui/gfx/font.h
+++ b/ui/gfx/font.h
@@ -79,6 +79,10 @@ class GFX_EXPORT Font {
   // string.
   int GetStringWidth(const base::string16& text) const;
 
+  // Returns the pixel width needed to display the specified string. Note that
+  // the fractional width might be returned in some platforms.
+  float GetStringWidthF(const base::string16& text) const;

[Alexei Svitkine (slow), 2013/10/07 21:43:39]

Is this actually needed? Does someone need to use Font::GetStringWidthF() that
can't use gfx::GetStringWidthF()?

We're trying to get rid of these APIs on Font - so I'd prefer to not introduce
this new version of the function on Font and PlatformFont.

[jianli, 2013/10/07 23:18:45]

Done.

+
   // Returns the expected number of horizontal pixels needed to display the
   // specified length of characters. Call GetStringWidth() to retrieve the
   // actual number.