Turn off the old compositing path for SPv2.

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 125 matching lines @@
         // We can synchronously perform layout.
         if (nextState == InPreLayout)
             return true;
         if (nextState == InPerformLayout)
             return true;
         // We can redundant arrive in the style clean state.
         if (nextState == StyleClean)
             return true;
         if (nextState == LayoutClean)
             return true;
-        if (nextState == InCompositingUpdate)
+        if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InCompositingUpdate)
+            return true;
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InPrePaint)
             return true;
         break;
     case InLayoutSubtreeChange:
         return nextState == LayoutSubtreeChangeClean;
     case LayoutSubtreeChangeClean:
         // We can synchronously recalc style.
         if (nextState == InStyleRecalc)
             return true;
         // We can synchronously perform layout.
         if (nextState == InPreLayout)
             return true;
         if (nextState == InPerformLayout)
             return true;
         // Can move back to style clean.
         if (nextState == StyleClean)
             return true;
         if (nextState == LayoutClean)
             return true;
-        if (nextState == InCompositingUpdate)
+        if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InCompositingUpdate)
+            return true;
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InPrePaint)
             return true;
         break;
     case InPreLayout:
         if (nextState == InStyleRecalc)
             return true;
         if (nextState == StyleClean)
             return true;
         if (nextState == InPreLayout)
             return true;
         break;
@@ skipping 15 matching lines @@
         if (nextState == InPreLayout)
             return true;
         if (nextState == InPerformLayout)
             return true;
         // We can redundantly arrive in the layout clean state. This situation
         // can happen when we call layout recursively and we unwind the stack.
         if (nextState == LayoutClean)
             return true;
         if (nextState == StyleClean)
             return true;
-        if (nextState == InCompositingUpdate)
+        if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InCompositingUpdate)
+            return true;
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InPrePaint)
             return true;
         break;
     case InCompositingUpdate:
+        DCHECK(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
         return nextState == CompositingClean;
     case CompositingClean:
+        DCHECK(!RuntimeEnabledFeatures::slimmingPaintV2Enabled());
         if (nextState == InStyleRecalc)
             return true;
         if (nextState == InPreLayout)
             return true;
         if (nextState == InCompositingUpdate)
             return true;
         if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
             if (nextState == InPrePaint)
                 return true;
         } else if (nextState == InPaintInvalidation) {
             return true;
         }
         break;
     case InPaintInvalidation:
         DCHECK(!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled());
         return nextState == PaintInvalidationClean;
     case PaintInvalidationClean:
         DCHECK(!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled());
         if (nextState == InStyleRecalc)
             return true;
         if (nextState == InPreLayout)
             return true;
         if (nextState == InCompositingUpdate)
             return true;
-        if (nextState == InPaint)
+        if (nextState == InPrePaint)
             return true;
         break;
     case InPrePaint:
-        if (nextState == PrePaintClean && RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
+        if (nextState == PrePaintClean)
             return true;
         break;
     case PrePaintClean:
-        if (!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
-            break;
         if (nextState == InPaint)
             return true;
         if (nextState == InStyleRecalc)
             return true;
         if (nextState == InPreLayout)
             return true;
-        if (nextState == InCompositingUpdate)
+        if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InCompositingUpdate)
+            return true;
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InPrePaint)
             return true;
         break;
     case InPaint:
         if (nextState == PaintClean)
             return true;
         break;
     case PaintClean:
         if (nextState == InStyleRecalc)
             return true;
         if (nextState == InPreLayout)
             return true;
-        if (nextState == InCompositingUpdate)
+        if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InCompositingUpdate)
+            return true;
+        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && nextState == InPrePaint)
             return true;
         break;
     case Stopping:
         return nextState == Stopped;
     case Stopped:
         return false;
     }
     return false;
 }
 
@@ skipping 74 matching lines @@
         DEBUG_STRING_CASE(Stopping);
         DEBUG_STRING_CASE(Stopped);
     }
 
     ASSERT_NOT_REACHED();
     return "Unknown";
 }
 #endif
 
 } // namespace blink