virtual/rootlayerscrolls failing on chromium.webkit/WebKit Win7 (dbg)

Type: build-failure

Builders failed on: 
- WebKit Win7 (dbg): 
  https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win7%20%28dbg%29

https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Win7__dbg_/8762/layout-test-results/results.html

Failing tests:
virtual/rootlayerscrolls/fast/scrolling/fractional-scroll-offset-iframe-fixed-position.html
virtual/rootlayerscrolls/fast/scrolling/fixed-position.html
virtual/rootlayerscrolls/fast/scrolling/scrollbar-tickmarks-styled.html
virtual/rootlayerscrolls/fast/scrolling/overflow-clip-with-page-scale.html
virtual/rootlayerscrolls/fast/scrolling/custom-scrollbar-style-applied-with-overflow-attribute.html
virtual/rootlayerscrolls/fast/scrolling/background-paint-scrolled-out-and-in.html
virtual/rootlayerscrolls/fast/scrolling/hide-scrollbars-in-frame.html
virtual/rootlayerscrolls/fast/scrolling/fractional-scroll-offset-fixed-position-non-composited.html
virtual/rootlayerscrolls/fast/scrolling/scrollbar-tickmarks-styled-after-onload.html
virtual/rootlayerscrolls/fast/scrolling/horizontal-overflow-quirks.html
virtual/rootlayerscrolls/fast/scrolling/background-paint-scrolled.html
virtual/rootlayerscrolls/scrollbars/layout-viewport-scrollbars-hidden.html
virtual/rootlayerscrolls/scrollbars/custom-scrollbar-thumb-inactive-pseudo.html
virtual/rootlayerscrolls/scrollbars/custom-scrollbar-thumb-focus-iframe-inactive-pseudo.html
virtual/rootlayerscrolls/scrollbars/avoid-double-scrollbars-when-html-element-is-not-the-renderview.html
virtual/rootlayerscrolls/scrollbars/custom-scrollbar-display.html
virtual/rootlayerscrolls/scrollbars/custom-scrollbar-with-incomplete-style.html
virtual/rootlayerscrolls/scrollbars/custom-scrollbar-inactive-only-on-windowinactive-selector.html
virtual/rootlayerscrolls/scrollbars/custom-scrollbar-changing-style.html
virtual/rootlayerscrolls/scrollbars/custom-scrollbar-adjust-on-inactive-pseudo.html


Stack trace:
[700:5024:0118/123123.090:628668:FATAL:layer_tree_impl.cc(559)] Check failed: !element_id_collision_detected. 
Backtrace:
	base::debug::StackTrace::StackTrace [0x0147EEC7+23]
	logging::LogMessage::~LogMessage [0x014CF1FB+59]
	cc::LayerTreeImpl::AddToElementMap [0x07413903+467]
	cc::LayerImpl::SetElementId [0x0713AA77+279]
	cc::Layer::PushPropertiesTo [0x0712A034+964]
	cc::PictureLayer::PushPropertiesTo [0x0714FFAF+31]
	cc::PushLayerList<cc::LayerTreeImpl> [0x074A07AE+510]
	cc::TreeSynchronizer::PushLayerProperties [0x074A40EF+31]
	cc::LayerTreeHostInProcess::FinishCommitOnImplThread [0x073FA1F0+912]
	cc::SingleThreadProxy::DoCommit [0x0749A41D+589]
	cc::SingleThreadProxy::CompositeImmediately [0x07499644+868]
	cc::LayerTreeHostInProcess::Composite [0x073F8A22+354]
	content::RenderWidgetCompositor::SynchronouslyComposite [0x126DB06B+219]
	??$Invoke@ABV?$WeakPtr@VRenderWidgetCompositor@content@@@base@@$$V@?$FunctorTraits@P8RenderWidgetCompositor@content@@AEXXZX@internal@base@@SAXP8RenderWidgetCompositor@content@@AEXXZABV?$WeakPtr@VRenderWidgetCompositor@content@@@2@@Z [0x126D5D38+24]
	??$MakeItSo@ABQ8RenderWidgetCompositor@content@@AEXXZABV?$WeakPtr@VRenderWidgetCompositor@content@@@base@@$$V@?$InvokeHelper@$00X@internal@base@@SAXABQ8RenderWidgetCompositor@content@@AEXXZABV?$WeakPtr@VRenderWidgetCompositor@content@@@2@@Z [0x126D5EB9+57]
	base::internal::Invoker<base::internal::BindState<void (__thiscall content::RenderWidgetCompositor::*)(void),base::WeakPtr<content::RenderWidgetCompositor> >,void __cdecl(void)>::RunImpl<void (__thiscall content::RenderWidgetCompositor::*const &)(void),st [0x126D6174+52]
	base::internal::Invoker<base::internal::BindState<void (__thiscall content::RenderWidgetCompositor::*)(void),base::WeakPtr<content::RenderWidgetCompositor> >,void __cdecl(void)>::Run [0x126DA924+36]
	base::internal::RunMixin<base::Callback<void __cdecl(void),0,0> >::Run [0x01484C74+68]
	base::debug::TaskAnnotator::RunTask [0x01484E0F+367]