Remove check for ssl_enabled for ConfigBuilder

[KiChjang]

Fixes #22252. This is a rebased version of #22253.

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This change is 

[servo-wpt-sync]

Error syncing changes upstream. Logs saved in error-snapshot-1545509473194.

[KiChjang]

Oh crud, something's wrong with the WPT sync. cc @jdm

[jdm]

In this case there's probably a merge conflict because we're 5 days behind.

[bors-servo]

☔ The latest upstream changes (presumably #22536) made this pull request unmergeable. Please resolve the merge conflicts.

[servo-wpt-sync]

Opened new PR for upstreamable changes.

Completed upstream sync of web-platform-test changes at web-platform-tests/wpt#14662.

[KiChjang]

r? @jdm

This should fix the problems I'm encountering on Windows. Essentially, the SSL config getter should ALWAYS return a record, regardless of whether or not SSL was enabled.

[KiChjang]

Should probably cc @jgraham as well.

[jdm]

@KiChjang What is the effect of these changes on your local build?

[jgraham]

I think this is probably OK.

[jdm]

Actually, I think I see how the SSL stuff works and why it's not working on Windows. Rather than making this change, I propose the following:

• in the build_env method in the msvc branch, add the openssl package's binary directory to the PATH

Since wptcommandline's --openssl-binary defaults to openssl, this will allow windows and non-windows platforms to take the same code path, and should allow running tests on Windows.

[jdm]

The other reasonable solution here would be modifying our WPT initialization to use the pregenerated certs from tests/wpt/web-platform-tests/tools/certs by setting the --ca-cert-path, --host-cert-path, and --host-key-path arguments appropriately.

[KiChjang]

@jdm Hrm, currently we do not require windows users to install openssl when configuring their system to build servo. Should we add that to the README.md? Or did you mean the python package that is called openssl?

[jdm]

We automatically download openssl as part of the windows bootstrapping process: https://github.com/servo/servo/blob/master/python/servo/packages.py#L10

[KiChjang]

So, I found out that the --ssl-type command line argument defaults to none, which causes the WPT runner to not use any SSL config at all, which means even if I did set the openssl binary path correctly for windows, it still wouldn't use any SSL config at all. @jdm Should we just default ssl_type to openssl altogether? Or would pregenerated make more sense here?

[KiChjang]

I'm also seeing that the code behaves extremely weirdly where defaults are applied after the CLI kwargs are parsed, and not during parsing. This leads to surprising behavior where if the ssl_type is changed in the middle of some code, it would somehow Just Work and use the correct openssl binary/certs, even though the corresponding CLI args aren't passed into wptrunner.

[jdm]

If I'm correct, your previous two comments refer to these bits of code:

• ssl_type defaults to none
• ssl_type is automatically changed to a non-none value, sometimes

This is why I suggested adding the openssl binary to the path on Windows. Really, though, everything will be easier if we set up our ca_cert_path/host_cert_path/host_key_path defaults to point at the pregenerated certs on all platforms. It should be possible to do that in set_defaults, which calls check_args.

[jdm]

Closing in favour of the description in #23133.

[servo-wpt-sync]

Error syncing changes upstream. Logs saved in error-snapshot-1553873359641.