blink: Cleanup core class forward declarations

third_party/WebKit/Source/core/page/scrolling/StickyPositionScrollingConstraints.h

 // Copyright 2016 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 StickyPositionScrollingConstraints_h
 #define StickyPositionScrollingConstraints_h
 
 #include "platform/geometry/FloatRect.h"
 
 namespace blink {
 
-class LayoutBoxModelObjectTest;
-
 class StickyPositionScrollingConstraints final {
  public:
   enum AnchorEdgeFlags {
     AnchorEdgeLeft = 1 << 0,
     AnchorEdgeRight = 1 << 1,
     AnchorEdgeTop = 1 << 2,
     AnchorEdgeBottom = 1 << 3
   };
   typedef unsigned AnchorEdges;
 
@@ skipping 70 matching lines @@
   float m_rightOffset;
   float m_topOffset;
   float m_bottomOffset;
   FloatRect m_scrollContainerRelativeContainingBlockRect;
   FloatRect m_scrollContainerRelativeStickyBoxRect;
 };
 
 }  // namespace blink
 
 #endif  // StickyPositionScrollingConstraints_h