message: We should not set isViewerEmbedded false. If it is false, the internal PDF viewer gets focused
  every time it reloaded when iframe based webviews enabled.
diff: @@ -55,14 +55,6 @@ class LateXWorkshopPdfViewer implements ILatexWorkshopPdfViewer {
  this.setupWebSocket()
  - this.onWillStartPdfViewer( () => {
  - // PDFViewerApplication detects whether it's embedded in an iframe (window.parent !== window)
  - // and if so it behaves more "discretely", eg it disables its history mechanism.
  - // We dont want that, so we unset the flag here (to keep viewer.js as vanilla as possible)
  - // https://github.com/James-Yu/LaTeX-Workshop/pull/447
  - PDFViewerApplication.isViewerEmbedded = false
  - })
  -
  this.onDidStartPdfViewer( () => {
  utils.callCbOnDidOpenWebSocket(this.socket, () => {
  this.send({type:'request_params', path:this.pdfFilePath})
  