Defer call to updateWidgetPositions() outside of RenderLayerScrollableArea.

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 7028b4aa100b78baf06075cc193ac4d75513c153..f0634078d63b1caaab80ba63f0fe69aaf5bb0a83 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -121,6 +121,7 @@ FrameView::FrameView(LocalFrame* frame)
     , m_inputEventsScaleFactorForEmulation(1)
     , m_layoutSizeFixedToFrameSize(true)
     , m_didScrollTimer(this, &FrameView::didScrollTimerFired)
+    , m_needsUpdateWidgetPositions(false)
 {
     ASSERT(m_frame);
     init();
@@ -2648,6 +2649,16 @@ void FrameView::paintOverhangAreas(GraphicsContext* context, const IntRect& hori
     ScrollView::paintOverhangAreas(context, horizontalOverhangArea, verticalOverhangArea, dirtyRect);
 }
 
+void FrameView::updateWidgetPositionsIfNeeded()
+{
+    if (!m_needsUpdateWidgetPositions)
+        return;
+
+    m_needsUpdateWidgetPositions = false;
+
+    updateWidgetPositions();
+}
+
 void FrameView::updateLayoutAndStyleForPainting()
 {
     // Updating layout can run script, which can tear down the FrameView.
@@ -2655,6 +2666,8 @@ void FrameView::updateLayoutAndStyleForPainting()
 
     updateLayoutAndStyleIfNeededRecursive();
 
+    updateWidgetPositionsIfNeeded();
+
     if (RenderView* view = renderView()) {
         TRACE_EVENT_INSTANT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "UpdateLayerTree", "frame", m_frame.get());
         // FIXME(361045): remove InspectorInstrumentation calls once DevTools Timeline migrates to tracing.