Add --enable-threaded-compositing for slimming virtual suite

LayoutTests/VirtualTestSuites

Index: LayoutTests/VirtualTestSuites
diff --git a/LayoutTests/VirtualTestSuites b/LayoutTests/VirtualTestSuites
index c505b79ea5bc0911a11abcfcfccd66b269941d44..20008e23ccf50f2e895242fa2bb75a9471cd2f0e 100644
--- a/LayoutTests/VirtualTestSuites
+++ b/LayoutTests/VirtualTestSuites
@@ -137,72 +137,72 @@
   {
     "prefix": "slimmingpaint",
     "base": "fast/block",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/inline",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/inline-block",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/images",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/table",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/text",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/overflow",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/borders",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/events",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "svg/text",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "svg/stroke",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "svg/foreignObject",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/css",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing"]
   },
   {
     "prefix": "slimmingpaint",
     "base": "fast/multicol",
-    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-region-based-columns"]
+    "args": ["--enable-slimming-paint", "--enable-impl-side-painting", "--enable-threaded-compositing", "--enable-region-based-columns"]
   },
   {
     "prefix": "rootlayerscrolls",