Layout Tests nested under an 'https' directory load over HTTPS directly.

Currently, we special-case tests under 'http/tests/ssl' to load directly
over HTTPS rather than HTTP. This allows us to avoid a 'window.location'
hop in the test itself, and is a generally useful ability when testing
behavior of features when behavior differs between HTTPS and HTTP
origins.

We're not using this useful ability, however: there are three tests in
that directory, two of which replicate tests under
'http/tests/security' and 'http/tests/navigation'.

This patch changes the special-case to include all tests with an
'https' directory in their paths, which will allow us to put the HTTP
and HTTPS versions of a feature's tests right next to each other.

This change was (briefly) discussed on blink-dev at
https://groups.google.com/a/chromium.org/d/msg/blink-dev/MqQFEjr43UQ/6ik0_OaFh1cJ

Review URL: https://codereview.chromium.org/527283002

git-svn-id: svn://svn.chromium.org/blink/trunk@181281 bbb929c8-8fbe-4397-9dbb-9b2b20218538