Reduce forward declarations in core/rendering

Source/core/rendering/RenderObject.h

Index: Source/core/rendering/RenderObject.h
diff --git a/Source/core/rendering/RenderObject.h b/Source/core/rendering/RenderObject.h
index 1ed3e8339d7cd2844a1093f2ee23aac3e0713294..3ca69eb961706f39f640a367821faa61d72ac0de 100644
--- a/Source/core/rendering/RenderObject.h
+++ b/Source/core/rendering/RenderObject.h
@@ -53,21 +53,15 @@ class HitTestLocation;
 class HitTestResult;
 class InlineBox;
 class InlineFlowBox;
-class Path;
 class Position;
 class PseudoStyleRequest;
 class RenderBoxModelObject;
-class RenderInline;
 class RenderBlock;
 class RenderFlowThread;
 class RenderGeometryMap;
 class RenderLayer;
 class RenderLayerModelObject;
-class RenderSVGResourceContainer;
-class RenderTable;
-class RenderTheme;
 class RenderView;
-class ResourceLoadPriorityOptimizer;
 class TransformState;
 
 struct PaintInfo;