message: Add `dispose()` to `DebouncedDoLater`
diff: @@ -111,7 +111,7 @@ export function doLaterFrame(func: Function): Disposable {
  * but will only fire the callback once. After the callback has been
  * run then it can be immediately reused.
  */
  -export class DebouncedDoLater {
  +export class DebouncedDoLater implements Disposable {
  private _laterDisposable: Disposable = null;
  constructor(private _callback: () => void, public delayMillis=0) {
  @@ -137,4 +137,9 @@ export class DebouncedDoLater {
  this.cancel();
  this._callback();
  }
  +
  + dispose(): void {
  + this.cancel();
  + this._callback = null;
  + }
  }
  