Introduce WPTServe for running W3C Blink Layout tests

Tools/Scripts/webkitpy/thirdparty/wpt/README.chromium

+W3C Web Platform Tests in Blink Layout Tests
+
+Design Doc: https://goo.gl/iXUaZd
+
+This directory contains checked out and reduced code from web-platform-tests

[jsbell, 2015/06/12 17:13:17]

We should get jgraham (W3C) to review this doc at some point. He may be able to
point out assumptions we're making about wpt that won't hold long term. (not a
blocker for ship, though)

[burnik, 2015/06/12 17:23:55]

Agreed. That's why I explicitly state the HEADs at WPTHeads to make the point.
:-)
I'll ping him to give some more insight.

+(https://github.com/w3c/web-platform-tests/) required to run WPT tests as part
+of Blink Layout Tests.
+
+For licensing, see README.chromium in parent directory
+(Tools/Scripts/webkitpy/thirdparty/README.chromium).
+
+Other files present in this directories are as follows:
+
+wpt.config.json
+===============
+The configuration file used when running WPTServe. Note that this file loads
+after wpt/config.default.json and this configuration gets merged onto it. When
+changing the ports (HTTP/S, WS/S), make sure to update the python code too.

[Dirk Pranke, 2015/06/12 22:25:02]

This is actually a file you wrote, right? Can we move it out of thirdparty
somewhere?

Also, do we really need both config files? Where does the
wpt/config.default.json file
come from? I don't see it on github, but maybe I'm not looking in the right
place?

We should try to avoid putting files we write under thirdparty/ dirs.

[burnik, 2015/06/15 10:35:10]

I would actually like to keep it in thirdparty for the time being. The
README.chromium clearly states what's being stored in the directory. I would
then move it once I'm confident on the way we should maintain the third party
repos.

A bigger issue here is the way serve works. It loads the config.default.json
first and then the specific config.json provided and merges them together.
Until we fix that in WPT, I would follow the intended use pattern.

https://github.com/w3c/web-platform-tests/blob/master/config.default.json

I would definitely avoid rewriting the config.default.json or add the config to
the actual WPT directory, because it's easier to see what's been done with the
checked in code.

+
+checkout.sh
+===========
+Run this script to delete the third party wpt directory (thirdparty/wpt/wpt)
+and perform a fresh checkout of the web-platform-tests code. When rolling in new

[jsbell, 2015/06/12 17:13:17]

Can you rewrite this more imperatively, i.e. keep short descriptions of the
files here, then have a section of the doc: "Steps to update wpt"

[burnik, 2015/06/15 10:35:10]

Done.

+versions of WPT support, use WPTHeads to adjust the HEAD positions before
+running ./checkout.sh. The script will also delete everything not listed in
+WPTWhiteList from the checked out directory.

[Dirk Pranke, 2015/06/12 22:25:02]

From what I can tell, we only actually need 

the serve/ and maybe sslutils directories from

https://github.com/w3c/wpt-tools

and then the wptserve directory from

https://github.com/w3c/wptserve

Can we check those into 

thirdparty/wpt_tools/{serve,sslutils}
thirdparty/wptserve/

and avoid a bunch of nested dirs?

Alternatively, we can consider just cloning the repos and pulling them via DEPS.

I'd like to be able to skip and/or simplify as many of these steps as possible
...

[burnik, 2015/06/15 10:35:10]

Actually, that's not all we need.

We need the wpt/serve script as it's the call into serve.main().
If we to decide to integrate the server into the same process as
run_webkit_tests then we can avoid it. Until then this script is a requirement.

I would also like to retain the directory structure imposed by WPT. Otherwise
this would require more wrapping of PYTHONPATH and other preconfiguration. As
I've stated in the DD, the behavior and structure should try to resemble what
one would experience in a local checkout of WPT.

I'm not sure if rolling into DEPS at this stage is really necessary, I believe
we should focus more on being able to run the existing tests on linux at this
point.

+
+WPTHeads
+========
+List of git commit-ish for the WPT repositories. File format is as follows:
+First line: HEAD position for web-platform-tests.
+Rest of lines: parent directory, submodule name, HEAD position for submodule.
+The submodule checkout is performed in order when running ./checkout.sh.
+
+WPTWhiteList
+============
+The explicit list of files being kept, everything else not on this list is
+deleted when running ./checkout.sh. Use this file to control what gets checked
+in and try to keep the list as small as possible (use what you need).
+
+**
+
+Running web-platform tests with enabled WPTServe on a local machine
+
+Starting run-webkit-tests with the --enable-wptserve flag will use the WPT
+serve for tests which live in LayoutTests/imported/web-platform-tests.
+
+WPTServe starts HTTP/S and WS/S servers as separate processes.
+
+The content_shell used to run the tests will receive the URL of each test
+(instead of a filename). The document root http://web-platform.test/ maps to
+LayoutTests/imported/web-platform-tests. HTTPS tests are enabled by default.
+
+Example run:
+
+./Tools/Scripts/run-webkit-tests \
+    --debug \
+    --enable-wptserve \
+    --no-new-test-results \
+    imported/web-platform-tests
+
+For setting up SSL, refer to Tools/Scripts/webkitpy/thirdparty/wpt/wpt/_certs
+(which gets generated on the first run) and Web Platform Tests Documentation.

[jsbell, 2015/06/12 17:13:17]

Include URL of the WPT docs?

[burnik, 2015/06/12 17:23:54]

When I find them, I'll make sure to add. So far, number of docs referring to SSL
in WPT: 
http://www.quickmeme.com/img/a5/a5482d8548fd094a6968efb4659393dfea89edeadeed8...

[burnik, 2015/06/15 10:35:10]

I've rewritten this in the "Configuration" section.