Allow InStyleRecalc and InPreLayout from CompositingForSlimmingPaintV2Clean

Previously almost every layout test crashed with
--enable-slimming-paint-v2 when advancing document lifecycle state from
CompositingForSlimmingPaintV2Clean to InStyleRecalc or InPreLayout.

Review URL: https://codereview.chromium.org/1297943005

git-svn-id: svn://svn.chromium.org/blink/trunk@200767 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/dom/DocumentLifecycle.cpp

@@ -213,6 +213,10 @@ bool DocumentLifecycle::canAdvanceTo(State nextState) const
     case CompositingForSlimmingPaintV2Clean:
         if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled())
             return false;
+        if (nextState == InStyleRecalc)
+            return true;
+        if (nextState == InPreLayout)
+            return true;
         if (nextState == InCompositingUpdate)
             return true;
         if (nextState == CompositingForSlimmingPaintV2Clean)