Enable new multicol for testing and experimental web platform features.

LayoutTests/VirtualTestSuites

Index: LayoutTests/VirtualTestSuites
diff --git a/LayoutTests/VirtualTestSuites b/LayoutTests/VirtualTestSuites
index 996c9a64c75affe7a610729369a331b156375b8b..e5575010294d172fc9f7b13f8f4ee32a06d56a30 100644
--- a/LayoutTests/VirtualTestSuites
+++ b/LayoutTests/VirtualTestSuites
@@ -103,6 +103,21 @@
   },
   {
     "prefix": "stable",
+    "base": "compositing/columns",
+    "args": ["--stable-release-mode"]
+  },
+  {
+    "prefix": "stable",
+    "base": "fast/multicol",
+    "args": ["--stable-release-mode"]
+  },
+  {
+    "prefix": "stable",
+    "base": "fast/pagination",
+    "args": ["--stable-release-mode"]
+  },
+  {
+    "prefix": "stable",
     "base": "web-animations-api",
     "args": ["--stable-release-mode"]
   },
@@ -123,21 +138,6 @@
     "args": ["--enable-threaded-compositing"]
   },
   {
-    "prefix": "regionbasedmulticol",
-    "base": "compositing/columns",
-    "args": ["--enable-region-based-columns"]
-  },
-  {
-    "prefix": "regionbasedmulticol",
-    "base": "fast/multicol",
-    "args": ["--enable-region-based-columns"]
-  },
-  {
-    "prefix": "regionbasedmulticol",
-    "base": "fast/pagination",
-    "args": ["--enable-region-based-columns"]
-  },
-  {
     "prefix": "slimmingpaint",
     "base": "fast/block",
     "args": ["--enable-slimming-paint"],
@@ -259,8 +259,8 @@
   {
     "prefix": "slimmingpaint",
     "base": "fast/multicol",
-    "args": ["--enable-slimming-paint", "--enable-region-based-columns"],
-    "reference_args": ["--enable-region-based-columns"]
+    "args": ["--enable-slimming-paint"],
+    "reference_args": []
   },
   {
     "prefix": "rootlayerscrolls",