It looks like WebGL maps have their own GPU exclusion list, or something. I launched Chrome with --ignore-gpu-blacklist and WebGL maps still refuses to run.
We do not have an exclusion list, but we do run a micro-benchmark on your machine to ensure your GPU will be powerful enough to handle MapsGL. You can try upgrading your drivers as well, which sometimes improves performance (looks like intel put out new device drivers for that chip about a year ago)
You could try enabling the "Override software rendering list" option in about:flags, although that is probably the same as the --ignore-gpu-blacklist option.