Cleanup: Remove LayoutRegion.

Source/core/layout/GeneratedChildren.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GeneratedChildren_h
 #define GeneratedChildren_h
 
 #include "core/layout/LayoutObject.h"
 
 namespace blink {
 
 // We only create "generated" child layoutObjects like one for first-letter if:
 // - the firstLetterBlock can have children in the DOM and
 // - the block doesn't have any special assumption on its text children.
 // This correctly prevents form controls from having such layoutObjects.
 static bool canHaveGeneratedChildren(const LayoutObject& layoutObject)
 {
     // FIXME: LayoutMedia::layout makes assumptions about what children are allowed
     // so we can't support generated content.
     if (layoutObject.isMedia() || layoutObject.isTextControl() || layoutObject.isMenuList())
         return false;
 
-    if (layoutObject.isLayoutRegion())
-        return true;
-
     // Input elements can't have generated children, but button elements can. We'll
     // write the code assuming any other button types that might emerge in the future
     // can also have children.
     if (layoutObject.isLayoutButton())
         return !isHTMLInputElement(*layoutObject.node());
 
     return layoutObject.canHaveChildren();
 }
 
 } // namespace blink
 
 #endif // GeneratedChildren_h