Bug 1526447 - remove unused NS_STYLE_GRID_REPEAT_* macros r=boris

Remove unused NS_STYLE_GRID_REPEAT_* macro definitions.

Differential Revision: https://phabricator.services.mozilla.com/D42664

--HG--
extra : moz-landing-system : lando

layout/style/nsStyleConsts.h

@@ -492,10 +492,6 @@ enum class StyleGridTrackBreadth : uint8_t {
   MinContent = 2,
 };
 
-// CSS Grid keywords for <auto-repeat>
-#define NS_STYLE_GRID_REPEAT_AUTO_FILL 0
-#define NS_STYLE_GRID_REPEAT_AUTO_FIT 1
-
 // defaults per MathML spec
 #define NS_MATHML_DEFAULT_SCRIPT_SIZE_MULTIPLIER 0.71f
 #define NS_MATHML_DEFAULT_SCRIPT_MIN_SIZE_PT 8