Got disabled in chromium 71 upgrade https://github.com/electron/electron/commit/798b2a3ffd55c477af6258f0afb71000c9f8ecde

/cc @brenca @codebytere 
atom/browser/osr/osr_render_widget_host_view.cc
const gfx::Range&,
    const std::vector<gfx::Rect>&) {}
gfx::Size OffScreenRenderWidgetHostView::GetCompositorViewportPixelSize()
    const {
  return gfx::ScaleToCeiledSize(GetRequestedRendererSize(),
                                current_device_scale_factor_);
}
content::RenderWidgetHostViewBase*
OffScreenRenderWidgetHostView::CreateViewForWidget(
    content::RenderWidgetHost* render_widget_host,
    content::RenderWidgetHost* embedder_render_widget_host,
    content::WebContentsView* web_contents_view) {
  if (render_widget_host->GetView()) {
    return static_cast<content::RenderWidgetHostViewBase*>(
        render_widget_host->GetView());
  }
  OffScreenRenderWidgetHostView* embedder_host_view = nullptr;
  if (embedder_render_widget_host) {
    embedder_host_view = static_cast<OffScreenRenderWidgetHostView*>(
        embedder_render_widget_host->GetView());
  }
  return new OffScreenRenderWidgetHostView(
      transparent_, true, embedder_host_view->GetFrameRate(), callback_,
      render_widget_host, embedder_host_view, size());
}
#if !defined(OS_MACOSX)
ui::Layer* OffScreenRenderWidgetHostView::DelegatedFrameHostGetLayer() const {