Convert Settings::rootLayerScrolls to RuntimeEnabledFeatures

third_party/WebKit/Source/core/paint/BoxPaintInvalidator.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/BoxPaintInvalidator.h"
 
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/ObjectPaintInvalidator.h"
 #include "core/paint/PaintInvalidator.h"
@@ skipping 110 matching lines @@
         return m_box.intersectsVisibleViewport() ? PaintInvalidationFull : PaintInvalidationDelayedFull;
     }
 
     if (m_box.isLayoutView()) {
         const LayoutView& layoutView = toLayoutView(m_box);
         // In normal compositing mode, root background doesn't need to be invalidated for
         // box changes, because the background always covers the whole document rect
         // and clipping is done by compositor()->m_containerLayer. Also the scrollbars
         // are always composited. There are no other box decoration on the LayoutView thus
         // we can safely exit here.
-        if (layoutView.usesCompositing() && (!layoutView.document().settings() || !layoutView.document().settings()->rootLayerScrolls()))
+        if (layoutView.usesCompositing() && !RuntimeEnabledFeatures::rootLayerScrollingEnabled())
             return reason;
     }
 
     // If the transform is not identity or translation, incremental invalidation is not applicable
     // because the difference between oldBounds and newBounds doesn't cover all area needing invalidation.
     // FIXME: Should also consider ancestor transforms since paintInvalidationContainer. crbug.com/426111.
     if (reason == PaintInvalidationIncremental
         && m_context.oldBounds != m_context.newBounds
         && m_context.paintInvalidationContainer != m_box
         && m_box.hasLayer() && m_box.layer()->transform()
@@ skipping 129 matching lines @@
 
     auto it = previousBoxSizesMap().find(&m_box);
     if (it != previousBoxSizesMap().end())
         return it->value.borderBoxSize;
 
     // We didn't save the old border box size because it was the same as the size of oldBounds.
     return previousBoundsSize;
 }
 
 } // namespace blink