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)

params[key] = new Uint8Array(value);
        } else if (value instanceof Uint8Array) {
          break; 
        } else if (typeof value === "string") {
          params[key] = stringToBytes(value);
        } else if (
          typeof value === "object" &&
          value !== null &&
          !isNaN(value.length)
        ) {
          params[key] = new Uint8Array(value);
        } else if (isArrayBuffer(value)) {
          params[key] = new Uint8Array(value);
        } else {
          throw new Error(
            "Invalid PDF binary data: either typed array, " +
              "string, or array-like object is expected in the data property."
          );
        }
        continue;
    }
    params[key] = value;
  }
  params.rangeChunkSize = params.rangeChunkSize || DEFAULT_RANGE_CHUNK_SIZE;
  params.CMapReaderFactory =
    params.CMapReaderFactory || DefaultCMapReaderFactory;
  params.ignoreErrors = params.stopAtErrors !== true;
  params.fontExtraProperties = params.fontExtraProperties === true;
  params.pdfBug = params.pdfBug === true;
  params.enableXfa = params.enableXfa === true;