Do not trigger compositing update on selection gap update for SPv2

Source/core/paint/DeprecatedPaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 1914 matching lines @@
             if (!depthSortDescendants)
                 break;
         }
     }
 
     return resultLayer;
 }
 
 void DeprecatedPaintLayer::blockSelectionGapsBoundsChanged()
 {
+    if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+        return;
+
     setNeedsCompositingInputsUpdate();
 }
 
 void DeprecatedPaintLayer::addBlockSelectionGapsBounds(const LayoutRect& bounds)
 {
     if (RuntimeEnabledFeatures::selectionPaintingWithoutSelectionGapsEnabled())
         return;
     m_blockSelectionGapsBounds.unite(enclosingIntRect(bounds));
     blockSelectionGapsBoundsChanged();
 }
@@ skipping 726 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif