Uses and returns the fractional width in text eliding

ui/gfx/render_text_mac.cc

Index: ui/gfx/render_text_mac.cc
diff --git a/ui/gfx/render_text_mac.cc b/ui/gfx/render_text_mac.cc
index 2fcea01b157dee17421a5af1de7c14adfef65601..d86975d063081de323c38633d541dcc5b9c26cd3 100644
--- a/ui/gfx/render_text_mac.cc
+++ b/ui/gfx/render_text_mac.cc
@@ -25,6 +25,11 @@ RenderTextMac::~RenderTextMac() {
 
 Size RenderTextMac::GetStringSize() {
   EnsureLayout();

[sky, 2013/10/08 02:12:56]

How about
return ToCeiledSize(GetStringSizeF())
?

[jianli, 2013/10/08 18:29:48]

Returning both ceiled width and height will cause test
RenderTextTest.StringSizeRespectsFontListMetrics to fail. This is because
[NSLayoutManager defaultLineHeightForFont] (called by Font::GetHeight) returns
the non-fractional height while CTLineGetTypographicBounds (used by
RenderTextMac in height computation) returns the fractional height.

+  return Size(std::ceil(string_size_.width()), string_size_.height());
+}
+
+SizeF RenderTextMac::GetStringSizeF() {
+  EnsureLayout();
   return string_size_;
 }
 
@@ -149,7 +154,7 @@ void RenderTextMac::EnsureLayout() {
   CGFloat font_list_baseline = font_list().GetBaseline();
   ascent = std::max(ascent, font_list_baseline);
   descent = std::max(descent, font_list_height - font_list_baseline);
-  string_size_ = Size(std::ceil(width), ascent + descent + leading);
+  string_size_ = SizeF(width, ascent + descent + leading);
   common_baseline_ = ascent;
 }