Uses and returns the fractional width in text eliding

ui/gfx/platform_font_mac.mm

 // 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/platform_font_mac.h"
 
 #include <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
 #include "base/mac/scoped_nsobject.h"
@@ skipping 45 matching lines @@
 }
 
 int PlatformFontMac::GetBaseline() const {
   return ascent_;
 }
 
 int PlatformFontMac::GetCapHeight() const {
   return cap_height_;
 }
 
-int PlatformFontMac::GetAverageCharacterWidth() const {
+float PlatformFontMac::GetAverageCharacterWidth() const {
   return average_width_;
 }
 
-int PlatformFontMac::GetStringWidth(const base::string16& text) const {
+float PlatformFontMac::GetStringWidth(const base::string16& text) const {
   return Canvas::GetStringWidth(text,
                                 Font(const_cast<PlatformFontMac*>(this)));
 }
 
-int PlatformFontMac::GetExpectedTextWidth(int length) const {
+float PlatformFontMac::GetExpectedTextWidth(int length) const {
   return length * average_width_;
 }
 
 int PlatformFontMac::GetStyle() const {
   return style_;
 }
 
 std::string PlatformFontMac::GetFontName() const {
   return font_name_;
 }
@@ skipping 64 matching lines @@
   return new PlatformFontMac(native_font);
 }
 
 // static
 PlatformFont* PlatformFont::CreateFromNameAndSize(const std::string& font_name,
                                                   int font_size) {
   return new PlatformFontMac(font_name, font_size);
 }
 
 }  // namespace gfx