message: in DisplayStyelState set viewFlags, clone parameter flags
diff: @@ -22,7 +22,11 @@ export abstract class DisplayStyleState extends ElementState {
  public get name(): string { return this.code.getValue(); }
  public get viewFlags(): ViewFlags { return this._viewFlags; }
  - public set viewFlags(flags: ViewFlags) { this._viewFlags = flags; this.setStyle("viewflags", flags); }
  + public set viewFlags(flags: ViewFlags) {
  + const viewFlags = flags.clone();
  + this._viewFlags = viewFlags;
  + this.setStyle("viewflags", viewFlags);
  + }
  public getStyles(): any { const p = this.jsonProperties as any; if (!p.styles) p.styles = new Object(); return p.styles; }
  public getStyle(name: string): any {
  