Reduce forward declarations in core/rendering

Source/core/rendering/RenderLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 48 matching lines @@
 #include "platform/graphics/CompositingReasons.h"
 #include "wtf/OwnPtr.h"
 
 namespace WebCore {
 
 class FilterEffectRenderer;
 class FilterOperations;
 class HitTestRequest;
 class HitTestResult;
 class HitTestingTransformState;
-class RenderFlowThread;
-class RenderGeometryMap;
 class CompositedLayerMapping;
 class RenderLayerCompositor;
-class RenderReplica;
 class RenderStyle;
 class TransformationMatrix;
 
 enum BorderRadiusClippingRule { IncludeSelfForBorderRadius, DoNotIncludeSelfForBorderRadius };
 enum IncludeSelfOrNot { IncludeSelf, ExcludeSelf };
 
 enum CompositingQueryMode {
     CompositingQueriesAreAllowed,
     CompositingQueriesAreOnlyAllowedInCertainDocumentLifecyclePhases
 };
@@ skipping 638 matching lines @@
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const WebCore::RenderLayer*);
 void showLayerTree(const WebCore::RenderObject*);
 #endif
 
 #endif // RenderLayer_h