[RLS] Don't create PaintLayerCompositor layers.

third_party/WebKit/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 5021 matching lines @@
 
   if (!page()->settings().getThreadedScrollingEnabled())
     reasons |= MainThreadScrollingReason::kThreadedScrollingDisabled;
 
   if (!frame.isLocalFrame())
     return;
 
   FrameView& frameView = *toLocalFrame(frame).view();
   if (frameView.shouldThrottleRendering())
     return;
-  if (!frameView.layerForScrolling())
-    return;
 
   reasons |= frameView.mainThreadScrollingReasonsPerFrame();
   if (GraphicsLayer* layerForScrolling = toLocalFrame(frame)
                                              .view()
                                              ->layoutViewportScrollableArea()
                                              ->layerForScrolling()) {
     if (WebLayer* platformLayerForScrolling =
             layerForScrolling->platformLayer()) {
       if (reasons) {
         platformLayerForScrolling->addMainThreadScrollingReasons(reasons);
@@ skipping 195 matching lines @@
 void FrameView::setAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   m_animationHost = std::move(host);
 }
 
 LayoutUnit FrameView::caretWidth() const {
   return LayoutUnit(getHostWindow()->windowToViewportScalar(1));
 }
 
 }  // namespace blink