b=383960, moz cairo: no longer needed: quartz-glyph-rounding.patch

gfx/cairo/README

@@ -24,8 +24,6 @@ Some specific things:
 
 max-font-size.patch: Clamp freetype font size to 1000 to avoid overflow issues
 
-quartz-glyph-rounding.patch: Round glyph positions, not advances, to float
-
 win32-scaled-font-size.patch: Add cairo_win32_font_face_create_for_logfontw_hfont,
 allow win32 scaled_fonts to rescale themselves properly to the required CTM
 and only use the font_face's hfont if we're sure it's appropriate