Move rendering/RenderLayer* to layout/

Source/core/layout/compositing/CompositingState.h

 // Copyright 2013 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 CompositingState_h
 #define CompositingState_h
 
 namespace blink {
 
 enum CompositingState {
     // The layer paints into its enclosing composited ancestor.
     NotComposited = 0,
 
     PaintsIntoOwnBacking = 1,
 
-    // In this state, the RenderLayer subtree paints into a backing that is shared by
-    // several RenderLayer subtrees.
+    // In this state, the Layer subtree paints into a backing that is shared by
+    // several Layer subtrees.
     PaintsIntoGroupedBacking = 2
 };
 
 } // namespace blink
 
 #endif // CompositingState_h