wasm: use emrun to run tests.html

emrun automates starting a web server, opening the .html
in the browser, capturing stdout and stderr, and the
return code from main().

https://emscripten.org/docs/compiling/Running-html-files-with-emrun.html

Change-Id: I03bb04e64f84e599fcfcbfbb4d8e9a4584e525f5
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/199555
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
1 file changed