[Layout API] Use ownerLayoutItem in updateScrollCorner()

third_party/WebKit/Source/core/frame/FrameView.cpp

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 2de7149867ceba3ba66028b8896f81be3eff77d8..7ec7e52dbf4abbb3fc5ad1deff667fd9865ebf01 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -2486,8 +2486,9 @@ void FrameView::updateScrollCorner()
 
         if (!cornerStyle) {
             // If we have an owning ipage/LocalFrame element, then it can set the custom scrollbar also.
-            if (LayoutPart* layoutObject = m_frame->ownerLayoutObject())
-                cornerStyle = layoutObject->getUncachedPseudoStyle(PseudoStyleRequest(PseudoIdScrollbarCorner), layoutObject->style());
+            LayoutPartItem layoutItem = m_frame->ownerLayoutItem();
+            if (!layoutItem.isNull())
+                cornerStyle = layoutItem.getUncachedPseudoStyle(PseudoStyleRequest(PseudoIdScrollbarCorner), layoutItem.style());
         }
     }