In the following spots a "MouseUp" eventName is being used, which does look inconsistent considering that the "Mouse Down"/"Mouse Enter"/"Mouse Exit" eventNames all have a space in them.
Is this inconsistency actually expected, or is it a simple typo? If the former, then a comment explaining *why* would be appropriate; otherwise we should just fix this :-)

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L806

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L945

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L1034

 - https://github.com/mozilla/pdf.js/blob/25b84ce84c95ba06d1ee57e578672048269c39c1/src/display/annotation_layer.js#L1168

/cc @calixteman 
constructor(
    parameters,
    {
      isRenderable = false,
      ignoreBorder = false,
      createQuadrilaterals = false,
    } = {}
  ) {
    this.isRenderable = isRenderable;
    this.data = parameters.data;
    this.layer = parameters.layer;
    this.page = parameters.page;
    this.viewport = parameters.viewport;
    this.linkService = parameters.linkService;
    this.downloadManager = parameters.downloadManager;
    this.imageResourcesPath = parameters.imageResourcesPath;
    this.renderInteractiveForms = parameters.renderInteractiveForms;
    this.svgFactory = parameters.svgFactory;
    this.annotationStorage = parameters.annotationStorage;
    this.enableScripting = parameters.enableScripting;
    this.hasJSActions = parameters.hasJSActions;
    this._mouseState = parameters.mouseState;
    if (isRenderable) {
      this.container = this._createContainer(ignoreBorder);
    }