Auto merge of #15111 - glennw:wr-update-generate, r=pcwalton

Update WR (radial gradients, generate_frame API, mac subpixel improvements, ANGLE shader support).

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tests/wpt/metadata-css/css-transforms-1_dev/html/regions-transforms-005.htm.ini

@@ -1,3 +1,4 @@
 [regions-transforms-005.htm]
   type: reftest
-  expected: FAIL
+  expected:
+    if os == "linux": FAIL

tests/wpt/metadata-css/css-transforms-1_dev/html/transform-table-006.htm.ini

@@ -1,3 +0,0 @@
-[transform-table-006.htm]
-  type: reftest
-  expected: FAIL

tests/wpt/metadata-css/css21_dev/html4/bidi-008b.htm.ini

@@ -0,0 +1,3 @@
+[bidi-008b.htm]
+  type: reftest
+  disabled: https://github.com/servo/servo/issues/15182