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)

pageIdsToKeep.add(pagesToKeep[i].id);
      }
      moveToEndOfArray(data, function (page) {
        return pageIdsToKeep.has(page.id);
      });
    }
    while (data.length > size) {
      data.shift().destroy();
    }
  };
  this.has = function (view) {
    return data.includes(view);
  };
}
function isSameScale(oldScale, newScale) {
  if (newScale === oldScale) {
    return true;
  }
  if (Math.abs(newScale - oldScale) < 1e-15) {
    
    
    return true;
  }
  return false;
}
/**
 * Simple viewer control to display PDF content/pages.
 * @implements {IRenderableView}
 */
class BaseViewer {