Load a PDF from PouchDB using the PDF.js Viewer. This code would go somewhere around line 2930 in web/viewer.js replacing the code that opens the PDF for Firefox and non B2G browsers. Example (note the parameters): http://test.local:5984/mount/_design/app/PDF-JS-Pouch-Viewer/web/viewer.html?db=testfiles&docId=helloworld&file=helloworld.pdf

open-pdf-from-pouchdb.js

  if(params.db && params.docId && params.file) {
    Pouch(params.db, function(err, db) {
      db.getAttachment(params.docId, params.file, function(err, res) { 
        var file = window.URL.createObjectURL(res)

        //#if (FIREFOX || MOZCENTRAL)
        //if (FirefoxCom.requestSync('getLoadingType') == 'passive') {
        //  PDFView.setTitleUsingUrl(file);
        //  PDFView.initPassiveLoading();
        //  return;
        //}
        //#endif

        //#if !B2G
          PDFView.open(file, 0);
        //#endif
      })
    })
  }
  else {
    //#if (FIREFOX || MOZCENTRAL)
    //if (FirefoxCom.requestSync('getLoadingType') == 'passive') {
    //  PDFView.setTitleUsingUrl(file);
    //  PDFView.initPassiveLoading();
    //  return;
    //}
    //#endif

    //#if !B2G
      PDFView.open(file, 0);
    //#endif
  }