Uses and returns the fractional width in text eliding

ui/gfx/font_list.cc

 // 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.
 
 #include "ui/gfx/font_list.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 177 matching lines @@
   // be taken into account to compute the pixels needed to display |text|.
   // Also this method, including one in Font class, should be deprecated and
   // client code should call Canvas::GetStringWidth(text, font_list) directly.
   // Our plan is as follows:
   //   1. Introduce the FontList version of Canvas::GetStringWidth().
   //   2. Make client code call Canvas::GetStringWidth().
   //   3. Retire {Font,FontList}::GetStringWidth().
   return GetPrimaryFont().GetStringWidth(text);
 }
 
+float FontList::GetStringWidthF(const base::string16& text) const {

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

Do we need this? Or can everything that needs it use gfx::GetStringWidthF() and
avoid introducing this API?

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

Done.

+  // Rely on the primary font metrics for the time being.
+  // TODO(yukishiino): Not only the first font, all the fonts in the list should
+  // be taken into account to compute the pixels needed to display |text|.
+  return GetPrimaryFont().GetStringWidthF(text);
+}
+
 int FontList::GetExpectedTextWidth(int length) const {
   // Rely on the primary font metrics for the time being.
   return GetPrimaryFont().GetExpectedTextWidth(length);
 }
 
 int FontList::GetFontStyle() const {
   if (font_style_ == -1)
     CacheFontStyleAndSize();
   return font_style_;
 }
@@ skipping 61 matching lines @@
     font_style_ = fonts_[0].GetStyle();
     font_size_ = fonts_[0].GetFontSize();
   } else {
     std::vector<std::string> font_names;
     ParseFontDescriptionString(font_description_string_, &font_names,
                                &font_style_, &font_size_);
   }
 }
 
 }  // namespace gfx