Revert Enable new multicol for testing and experimental web platform features.

LayoutTests/VirtualTestSuites

Index: LayoutTests/VirtualTestSuites
diff --git a/LayoutTests/VirtualTestSuites b/LayoutTests/VirtualTestSuites
index d5c6207a95276ffc7ee94b2351e342a33ca4e8c3..1ca6c5cf7ea482631ea33ef8fd57c34b82d2db3a 100644
--- a/LayoutTests/VirtualTestSuites
+++ b/LayoutTests/VirtualTestSuites
@@ -103,21 +103,6 @@
   },
   {
     "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"]
   },
@@ -138,6 +123,21 @@
     "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"],
@@ -379,8 +379,8 @@
   {
     "prefix": "slimmingpaint",
     "base": "fast/multicol",
-    "args": ["--enable-slimming-paint"],
-    "reference_args": []
+    "args": ["--enable-slimming-paint", "--enable-region-based-columns"],
+    "reference_args": ["--enable-region-based-columns"]
   },
   {
     "prefix": "rootlayerscrolls",