I was wondering if WebGL is considered stable enough to be enabled by default. It makes some PDFs render much faster and it has been off by default for a while now, so we have had quite some time to test it.

If we decide to enable WebGL by default, we should not forget to update https://github.com/mozilla/pdf.js/blob/master/extensions/chromium/preferences_schema.json#L39 as well.

/cc @yurydelendik 
/cc @Snuffleupagus (because IIRC you were testing WebGL too)

PDFViewerApplication.pdfViewer.scrollMode = evt.mode;
}
function webViewerSwitchSpreadMode(evt) {
  PDFViewerApplication.pdfViewer.spreadMode = evt.mode;
}
function webViewerDocumentProperties() {
  PDFViewerApplication.pdfDocumentProperties.open();
}
function webViewerFind(evt) {
  PDFViewerApplication.findController.executeCommand("find" + evt.type, {
    query: evt.query,
    phraseSearch: evt.phraseSearch,
    caseSensitive: evt.caseSensitive,
    entireWord: evt.entireWord,
    highlightAll: evt.highlightAll,
    findPrevious: evt.findPrevious,
  });
}
function webViewerFindFromUrlHash(evt) {
  PDFViewerApplication.findController.executeCommand("find", {
    query: evt.query,
    phraseSearch: evt.phraseSearch,
    caseSensitive: false,
    entireWord: false,
    highlightAll: true,
    findPrevious: false,
  });
}
function webViewerUpdateFindMatchesCount({ matchesCount }) {