Uses and returns the fractional width in text eliding

ui/gfx/platform_font_ios.mm

Index: ui/gfx/platform_font_ios.mm
diff --git a/ui/gfx/platform_font_ios.mm b/ui/gfx/platform_font_ios.mm
index cfc69cf4964bfa0b6573220e203300c672a22273..93df0aac90791e93b394e8be43a2fa83e8cb15ba 100644
--- a/ui/gfx/platform_font_ios.mm
+++ b/ui/gfx/platform_font_ios.mm
@@ -51,16 +51,16 @@ int PlatformFontIOS::GetBaseline() const {
   return ascent_;
 }
 
-int PlatformFontIOS::GetAverageCharacterWidth() const {
+float PlatformFontIOS::GetAverageCharacterWidth() const {
   return average_width_;
 }
 
-int PlatformFontIOS::GetStringWidth(const base::string16& text) const {
+float PlatformFontIOS::GetStringWidth(const base::string16& text) const {
   NSString* ns_text = base::SysUTF16ToNSString(text);
   return [ns_text sizeWithFont:GetNativeFont()].width;
 }
 
-int PlatformFontIOS::GetExpectedTextWidth(int length) const {
+float PlatformFontIOS::GetExpectedTextWidth(int length) const {
   return length * average_width_;
 }