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)

}
        }
        ctx.putImageData(chunkImgData, 0, j);
        j += FULL_CHUNK_HEIGHT;
      }
      if (i < totalChunks) {
        elemsInThisChunk = width * partialChunkHeight * 4;
        dest.set(src.subarray(srcPos, srcPos + elemsInThisChunk));
        if (hasTransferMaps) {
          for (let k = 0; k < elemsInThisChunk; k += 4) {
            if (transferMapRed) {
              dest[k + 0] = transferMapRed[dest[k + 0]];
            }
            if (transferMapGreen) {
              dest[k + 1] = transferMapGreen[dest[k + 1]];
            }
            if (transferMapBlue) {
              dest[k + 2] = transferMapBlue[dest[k + 2]];
            }
          }
        }
        ctx.putImageData(chunkImgData, 0, j);
      }
    } else if (imgData.kind === ImageKind.RGB_24BPP) {
      
      const hasTransferMaps = !!(
        transferMapRed ||
        transferMapGreen ||
        transferMapBlue
      );