7486;css leanbox
7487: LeanBoxCreator
7489: refactor
7490: fix
7492
7494: refactor WebDocumentParser
7496:
7498
7500: TopBoxInputEventBridge
7501
7508: move event code to TopBoxInputBridge
7509: HitPoint
7515: IHitElement
7517: fix OnMouseDown,GetElementGlobalLocation
7518: fix
7522:HitPointChain abstraction
7529:
7531: errs!
7532P: LayoutFarm.RenderTree

rename from LeanRenderer
7534