Run virtual/stable/paint/invalidation for non-SlimmingPaintInvalidation

Previously, we ran
virtual/spinvalidation/paint/invalidation with --enable-slimming-paint-invalidation
and skipped paint/invalidation.

Now remove virtual/spinvalidation and run
paint/invalidation with --enable-slimming-paint-invalidation just like all other
layout tests, and virtual/stable/paint/invalidation without experimental features
(including SlimmingPaintInvalidation).

This CL basically copies original baselines of virtual/spinvalidation/paint/invalidation
to paint/invalidation, and original baselines of paint/invalidation to
virtual/stable/paint/invalidation if the original baselines were different from the
new baselines of paint/invalidation.

BUG=646176

Review-Url: https://codereview.chromium.org/2620603002
Cr-Commit-Position: refs/heads/master@{#442348}
diff --git a/third_party/WebKit/LayoutTests/VirtualTestSuites b/third_party/WebKit/LayoutTests/VirtualTestSuites
index 26cb148b..1d1ac66d 100644
--- a/third_party/WebKit/LayoutTests/VirtualTestSuites
+++ b/third_party/WebKit/LayoutTests/VirtualTestSuites
@@ -99,6 +99,11 @@
     "args": ["--stable-release-mode"]
   },
   {
+    "prefix": "stable",
+    "base": "paint/invalidation",
+    "args": ["--stable-release-mode"]
+  },
+  {
     "prefix": "android",
     "base": "fullscreen",
     "args": ["--enable-threaded-compositing",
@@ -346,36 +351,6 @@
     "args": ["--enable-blink-features=FeaturePolicy"]
   },
   {
-    "prefix": "spinvalidation",
-    "base": "compositing",
-    "args": ["--enable-blink-features=SlimmingPaintInvalidation"]
-  },
-  {
-    "prefix": "spinvalidation",
-    "base": "css3",
-    "args": ["--enable-blink-features=SlimmingPaintInvalidation"]
-  },
-  {
-    "prefix": "spinvalidation",
-    "base": "fast",
-    "args": ["--enable-blink-features=SlimmingPaintInvalidation"]
-  },
-  {
-    "prefix": "spinvalidation",
-    "base": "paint",
-    "args": ["--enable-blink-features=SlimmingPaintInvalidation"]
-  },
-  {
-    "prefix": "spinvalidation",
-    "base": "printing",
-    "args": ["--enable-blink-features=SlimmingPaintInvalidation"]
-  },
-  {
-    "prefix": "spinvalidation",
-    "base": "svg",
-    "args": ["--enable-blink-features=SlimmingPaintInvalidation"]
-  },
-  {
     "prefix": "mojo-localstorage",
     "base": "imported/wpt/webstorage",
     "args": ["--mojo-local-storage"]