(WIP) Invalidation during painting (for synchronized painting)

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

Index: third_party/WebKit/Source/core/dom/DocumentLifecycle.cpp
diff --git a/third_party/WebKit/Source/core/dom/DocumentLifecycle.cpp b/third_party/WebKit/Source/core/dom/DocumentLifecycle.cpp
index 5e9e11c7bdf9c8dbfd5f116d04963ba18d66f48c..66f2602c1992da50dc77c45ffa511c1a340c4d51 100644
--- a/third_party/WebKit/Source/core/dom/DocumentLifecycle.cpp
+++ b/third_party/WebKit/Source/core/dom/DocumentLifecycle.cpp
@@ -197,24 +197,28 @@ bool DocumentLifecycle::canAdvanceTo(LifecycleState nextState) const
             return true;
         if (nextState == InCompositingUpdate)
             return true;
-        if (nextState == InPaintInvalidation)
+        if (nextState == InPaintInvalidation && !RuntimeEnabledFeatures::slimmingPaintV2Enabled())
             return true;
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+            if (nextState == InUpdatePaintProperties)
+                return true;
+        } else if (nextState == InPaint) {
+            return true;
+        }
         break;
     case InPaintInvalidation:
+        ASSERT(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
         return nextState == PaintInvalidationClean;
     case PaintInvalidationClean:
+        ASSERT(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
         if (nextState == InStyleRecalc)
             return true;
         if (nextState == InPreLayout)
             return true;
         if (nextState == InCompositingUpdate)
             return true;
-        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
-            if (nextState == InUpdatePaintProperties)
-                return true;
-        } else if (nextState == InPaint) {
+        if (nextState == InPaint)
             return true;
-        }
         break;
     case InUpdatePaintProperties:
         if (nextState == UpdatePaintPropertiesClean && RuntimeEnabledFeatures::slimmingPaintV2Enabled())