Update WR (ellipse border-radius clip, preserve-3d functionality).

tests/wpt/metadata-css/compositing-1_dev/html/mix-blend-mode-intermediate-element-overflow-hidden-and-border-radius.htm.ini

@@ -1,4 +0,0 @@
-[mix-blend-mode-intermediate-element-overflow-hidden-and-border-radius.htm]
-  type: reftest
-  expected:
-    if os == "linux": FAIL

tests/wpt/metadata-css/css-backgrounds-3_dev/html4/border-bottom-left-radius-010.htm.ini

@@ -1,3 +0,0 @@
-[border-bottom-left-radius-010.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css-backgrounds-3_dev/html4/border-bottom-right-radius-010.htm.ini

@@ -1,3 +0,0 @@
-[border-bottom-right-radius-010.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css-backgrounds-3_dev/html4/border-radius-clipping.htm.ini

@@ -1,3 +1,3 @@
 [border-radius-clipping.htm]
   type: reftest
-  expected: FAIL
+  disabled: https://github.com/servo/webrender/issues/1256

tests/wpt/metadata-css/css-backgrounds-3_dev/html4/border-top-left-radius-010.htm.ini

@@ -1,3 +0,0 @@
-[border-top-left-radius-010.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css-backgrounds-3_dev/html4/border-top-right-radius-010.htm.ini

@@ -1,3 +0,0 @@
-[border-top-right-radius-010.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css-transforms-1_dev/html/transform-3d-rotateY-stair-above-001.htm.ini

@@ -0,0 +1,3 @@
+[transform-3d-rotateY-stair-above-001.htm]
+  type: reftest
+  expected: FAIL

tests/wpt/metadata-css/css-transforms-1_dev/html/transform-3d-rotateY-stair-below-001.htm.ini

@@ -1,3 +0,0 @@
-[transform-3d-rotateY-stair-below-001.htm]
-  type: reftest
-  expected: FAIL