Fix broken preferred widths optimization involving subtree layout roots

Source/core/layout/LayoutBox.cpp

Index: Source/core/layout/LayoutBox.cpp
diff --git a/Source/core/layout/LayoutBox.cpp b/Source/core/layout/LayoutBox.cpp
index a73c9fa68a333709f851161cef7003549fd8c997..8a34c30dccc7a58dc3d8f4122b9bdc57ed093c72 100644
--- a/Source/core/layout/LayoutBox.cpp
+++ b/Source/core/layout/LayoutBox.cpp
@@ -1946,10 +1946,6 @@ void LayoutBox::computeLogicalWidth(LogicalExtentComputedValues& computedValues)
         return;
     }
 
-    // If layout is limited to a subtree, the subtree root's logical width does not change.
-    if (node() && view()->frameView() && view()->frameView()->isLayoutRoot(*this))
-        return;
-
     // The parent box is flexing us, so it has increased or decreased our
     // width.  Use the width from the style context.
     // FIXME: Account for writing-mode in flexible boxes.