Uses and returns the fractional width in text eliding

ui/gfx/font.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_GFX_FONT_H_
 #define UI_GFX_FONT_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 61 matching lines @@
   // Returns the cap height of the font.
   int GetCapHeight() const;
 
   // Returns the average character width for the font.
   int GetAverageCharacterWidth() const;
 
   // Returns the number of horizontal pixels needed to display the specified
   // 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.
   int GetExpectedTextWidth(int length) const;
 
   // Returns the style of the font.
   int GetStyle() const;
 
   // Returns the font name in UTF-8.
   std::string GetFontName() const;
@@ skipping 16 matching lines @@
   PlatformFont* platform_font() const { return platform_font_.get(); }
 
  private:
   // Wrapped platform font implementation.
   scoped_refptr<PlatformFont> platform_font_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_FONT_H_