(WIP) Paint invalidation for slimming paint v2

Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 2439 matching lines @@
         // This was required for slimming paint v1 but is only temporarily
         // needed for slimming paint v2.
         view->compositor()->updateIfNeededRecursive();
         scrollContentsIfNeededRecursive();
 
         ASSERT(lifecycle().state() >= DocumentLifecycle::CompositingClean);
 
         if (phases == OnlyUpToCompositingCleanPlusScrolling)
             return;
 
-        invalidateTreeIfNeededRecursive();
+        if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+            invalidateTreeIfNeededRecursive();
 
         if (view->compositor()->inCompositingMode())
             scrollingCoordinator()->updateAfterCompositingChangeIfNeeded();
 
         updateCompositedSelectionIfNeeded();
 
         if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
             paintForSlimmingPaintV2();
             if (phases == OnlyUpToPaintForSlimmingPaintV2Clean)
                 return;
@@ skipping 1501 matching lines @@
 
     if (!graphicsLayer)
         return;
 
     DeprecatedPaintLayer::mapRectToPaintInvalidationBacking(localFrame->contentLayoutObject(), paintInvalidationContainer, viewRect);
 
     graphicsLayerTimingRequests.add(graphicsLayer, Vector<std::pair<int64_t, WebRect>>()).storedValue->value.append(std::make_pair(m_frame->frameID(), enclosingIntRect(viewRect)));
 }
 
 } // namespace blink