Bug 1616994 - Merge layout/reftests/backgrounds/gradient and layout/reftests/css-gradients. r=mattwoodrow

Differential Revision: https://phabricator.services.mozilla.com/D63559

--HG--
rename : layout/reftests/backgrounds/gradient/color-stop-clamp-interpolation-ref.html => layout/reftests/css-gradients/color-stop-clamp-interpolation-ref.html
rename : layout/reftests/backgrounds/gradient/color-stop-clamp-interpolation.html => layout/reftests/css-gradients/color-stop-clamp-interpolation.html
rename : layout/reftests/backgrounds/gradient/linear-gradient-repeated-ref.html => layout/reftests/css-gradients/linear-gradient-repeated-ref.html
rename : layout/reftests/backgrounds/gradient/linear-gradient-repeated.html => layout/reftests/css-gradients/linear-gradient-repeated.html
rename : layout/reftests/backgrounds/gradient/scaled-color-stop-position-ref.html => layout/reftests/css-gradients/scaled-color-stop-position-ref.html
rename : layout/reftests/backgrounds/gradient/scaled-color-stop-position.html => layout/reftests/css-gradients/scaled-color-stop-position.html
extra : moz-landing-system : lando

layout/reftests/backgrounds/gradient/reftest.list

@@ -1,3 +0,0 @@
-== scaled-color-stop-position.html scaled-color-stop-position-ref.html
-fuzzy-if(webrender&&winWidget,0-1,0-387) == color-stop-clamp-interpolation.html color-stop-clamp-interpolation-ref.html
-== linear-gradient-repeated.html linear-gradient-repeated-ref.html

layout/reftests/css-gradients/reftest.list

@@ -104,3 +104,7 @@ fuzzy(0-2,0-800000) == large-gradient-5.html large-gradient-5-ref.html
 == 1224761-1.html 1224761-1-ref.html
 
 fuzzy(0-4,0-800000) == mask-gradient-translucent-end-color-1.html mask-gradient-translucent-end-color-1-ref.html
+
+== scaled-color-stop-position.html scaled-color-stop-position-ref.html
+fuzzy-if(webrender&&winWidget,0-1,0-387) == color-stop-clamp-interpolation.html color-stop-clamp-interpolation-ref.html
+== linear-gradient-repeated.html linear-gradient-repeated-ref.html