Scale the font size to pixels from pt. It seems like the font librari…

…es are expecting pixels, not points like the docs say. The glyph advance is also scaled slightly to match what is show in Firefox.

src/components/gfx/platform/macos/font.rs

@@ -150,7 +150,8 @@ impl FontHandleMethods for FontHandle {
                                                           &glyphs[0],
                                                           ptr::null(),
                                                           1);
-        Some(advance as FractionalPixel)
+        // TODO; On mac the font spacing looks a little small. Need to figure out why.
+        Some(advance * 1.08f as FractionalPixel)
     }
 
     fn get_metrics(&self) -> FontMetrics {
@@ -169,10 +170,9 @@ impl FontHandleMethods for FontHandle {
             underline_offset: Au::from_pt(self.ctfont.underline_position() as float),
             leading:          Au::from_pt(self.ctfont.leading() as float),
             x_height:         Au::from_pt(self.ctfont.x_height() as float),
-            // TODO: the ascent and descent need to be scaled by the pt_size, figure out why
             em_size:          em_size,
-            ascent:           ascent * em_size / (ascent + descent),
-            descent:          descent * em_size / (ascent + descent),
+            ascent:           ascent,
+            descent:          descent,
             max_advance:      Au::from_pt(bounding_rect.size.width as float)
         };
 

src/components/main/layout/box.rs

@@ -763,7 +763,7 @@ pub impl RenderBox {
         };
 
         FontStyle {
-            pt_size: font_size,
+            pt_size: font_size * 96f / 72f, // TODO: scale to pt
             weight: FontWeight300,
             italic: italic,
             oblique: oblique,