Ensure that if FrameView::isScrollable() is false, the assoc WebLayer is, too.

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 91a37524021e1d8c599965b0db2654ebe5726af7..90ef138b631e8c15ec027cc4e30f7b6e73d843e4 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -2598,6 +2598,19 @@ IntRect FrameView::scrollableAreaBoundingBox() const
     return ownerRenderer->absoluteContentQuad().enclosingBoundingBox();
 }
 
+bool FrameView::hasOverflow() const
+{
+    IntSize contentsSize = this->contentsSize();
+    IntSize visibleContentSize = visibleContentRect().size();
+    return contentsSize.height() > visibleContentSize.height() || contentsSize.width() > visibleContentSize.width();
+}
+
+bool FrameView::isVisibleToHitTesting() const
+{
+    HTMLFrameOwnerElement* owner = m_frame->ownerElement();
+    return !owner || (owner->renderer() && owner->renderer()->visibleToHitTesting());
+}
+
 bool FrameView::isScrollable()
 {
     // Check for:
@@ -2607,14 +2620,11 @@ bool FrameView::isScrollable()
     // 4) scrolling: no;
 
     // Covers #1
-    IntSize contentsSize = this->contentsSize();
-    IntSize visibleContentSize = visibleContentRect().size();
-    if ((contentsSize.height() <= visibleContentSize.height() && contentsSize.width() <= visibleContentSize.width()))
+    if (!hasOverflow())
         return false;
 
     // Covers #2.
-    HTMLFrameOwnerElement* owner = m_frame->ownerElement();
-    if (owner && (!owner->renderer() || !owner->renderer()->visibleToHitTesting()))
+    if (!isVisibleToHitTesting())
         return false;
 
     // Cover #3 and #4.