Keep track of multiple layout roots

Source/core/layout/LayoutObject.cpp

Index: Source/core/layout/LayoutObject.cpp
diff --git a/Source/core/layout/LayoutObject.cpp b/Source/core/layout/LayoutObject.cpp
index 673b5f869d1d61c1b81de420eab58e240e82ae8b..7754ebf5d5cceef4a510df882f0606d4aa197535 100644
--- a/Source/core/layout/LayoutObject.cpp
+++ b/Source/core/layout/LayoutObject.cpp
@@ -2274,17 +2274,9 @@ bool LayoutObject::isSelectionBorder() const
 
 inline void LayoutObject::clearLayoutRootIfNeeded() const
 {
-    if (frame()) {
-        if (FrameView* view = frame()->view()) {
-            if (view->layoutRoot() == this) {
-                if (!documentBeingDestroyed())
-                    ASSERT_NOT_REACHED();
-                // This indicates a failure to layout the child, which is why
-                // the layout root is still set to |this|. Make sure to clear it
-                // since we are getting destroyed.
-                view->clearLayoutSubtreeRoot();
-            }
-        }
+    if (FrameView* view = frameView()) {
+        if (!documentBeingDestroyed())
+            view->clearLayoutSubtreeRoot(this);
     }
 }