Remove assorted unnecessary includes in core/layout/

third_party/WebKit/Source/core/layout/ClipRectsCache.h

 // Copyright 2014 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 ClipRectsCache_h
 #define ClipRectsCache_h
 
 #include "core/layout/ClipRects.h"
 
 #if ENABLE(ASSERT)
-#include "core/layout/LayoutBox.h" // For OverlayScrollbarClipBehavior.
+#include "core/layout/ScrollEnums.h" // For OverlayScrollbarClipBehavior.
 #endif
 
 namespace blink {
 
 class PaintLayer;
 
 enum ClipRectsCacheSlot {
     // Relative to the ancestor treated as the root (e.g. transformed layer). Used for hit testing.
     RootRelativeClipRects,
     RootRelativeClipRectsIgnoringViewportClip,
@@ skipping 36 matching lines @@
         ASSERT(slot < NumberOfClipRectsCacheSlots);
         m_entries[slot] = Entry();
     }
 private:
     Entry m_entries[NumberOfClipRectsCacheSlots];
 };
 
 } // namespace blink
 
 #endif // ClipRectsCache_h