Fix unscrollable scrollers after closing a <dialog>.

third_party/WebKit/Source/core/dom/Element.cpp

Index: third_party/WebKit/Source/core/dom/Element.cpp
diff --git a/third_party/WebKit/Source/core/dom/Element.cpp b/third_party/WebKit/Source/core/dom/Element.cpp
index 047e339cba3e817a5c7eb056291cb3d2776f7584..91e167471b1e1107853def35776c51912c600518 100644
--- a/third_party/WebKit/Source/core/dom/Element.cpp
+++ b/third_party/WebKit/Source/core/dom/Element.cpp
@@ -3391,6 +3391,11 @@ void Element::setIsInTopLayer(bool inTopLayer) {
   // correct sibling order under LayoutView according to its top layer position,
   // or in its usual place if not in the top layer.
   lazyReattachIfAttached();
+
+  // PaintLayerScrollableArea::updateAfterLayout depends on top layer state
+  // via LayoutObject::visibleToHitTesting. See crbug.com/633520 for details.
+  document().layoutView()->setNeedsLayout(

[szager1, 2016/10/17 19:16:30]

Can we condition this on (layoutObject() && layoutObject()->hasOverflowClip())?

[esprehn, 2016/10/17 19:19:58]

This belongs in Document::removeFromTopLayer

[skobes, 2016/10/17 19:45:30]

We can't - the dialog itself is not a scroller.

[skobes, 2016/10/17 19:45:30]

Done.

+      LayoutInvalidationReason::TopLayerChanged);
 }
 
 void Element::requestPointerLock() {