WebLocalFrameImpl::printPage needs to ensure layout, style, and compositing are up-to-date

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index dcfd8cc80098481ba442eb978c4564b6f1906784..b12530ace8d2e8c6683ee59379db78059578f113 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -2555,6 +2555,7 @@ void FrameView::paintContents(GraphicsContext* p, const IntRect& rect)
     }
 
     RELEASE_ASSERT(!needsLayout());
+    ASSERT(document->lifecycle().state() >= DocumentLifecycle::CompositingClean);
 
     TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "Paint", "data", InspectorPaintEvent::data(renderView, rect, 0));
     TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline.stack"), "CallStack", "stack", InspectorCallStackEvent::currentCallStack());