Checkpoint work to import new tests from the w3c repos.

Add update-w3c-deps script to Tools/Scripts

This is a meta-import script that is responsible for doing all the
git shenanigans to import new versions of the W3C Test repos. It uses import-w3c-tests to do the heavy lifting, but also does all of the git manipulation necessary to ensure clean version history.

This patch also adds a 'W3CImportExpectations' files that lists which directories should be ignored during an import (i.e., it acts as a blacklist, so that we will otherwise pick up new changes automatically).

Note that this script does *not* automatically push anything to a source repo. The user still needs to verify that the import works, update any TestExpectations suppressions, and push the repo changes back to the Blink mirrors of the W3C repos.

BUG=242329
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169082

[Dirk Pranke, 2014-02-07 02:32:59]

Please take a look. The process is still a bit awkward, but getting cleaner.

Now, doing a new roll will be mostly:

1. run update-w3c-deps from the top of the blink repo
2. run run-webkit-tests once locally to sanity check the results
3. push the new commits to the blink mirrors
4. Do the actual DEPS roll.

Which shouldn't be *too* painful.

[ojan, 2014-02-08 00:36:28]

lgtm

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
File Tools/Scripts/update-w3c-deps (right):

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
Tools/Scripts/update-w3c-deps:34: blink_commitish = cmd.run(['git', 'show-ref',
'HEAD']).split()[0]
Should this assert you're in a clean checkout? FIXME would be fine.

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
Tools/Scripts/update-w3c-deps:46: if status and not 'nothing to commit, working
directory clean' in status:
This is kind of gross. webkitpy git does the following:
return self._run_git(['diff', 'HEAD', '--no-renames', '--name-only']) != ""

Seems a little better to me.

Also, do you not want to check also that there are no local commits? Again,
FIXME would be fine.

[Dirk Pranke, 2014-02-08 01:04:30]

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
File Tools/Scripts/update-w3c-deps (right):

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
Tools/Scripts/update-w3c-deps:34: blink_commitish = cmd.run(['git', 'show-ref',
'HEAD']).split()[0]
On 2014/02/08 00:36:28, ojan wrote:
> Should this assert you're in a clean checkout? FIXME would be fine.

I'm not actually sure you want to assert, but I have been waffling on this. Case
in point - the latest roll I have posted actually needed this patch local, and
I've been waffling on whether to commit that roll before this patch landed. At
the very least, warning that you're not in a clean checkout is a good idea (and
possibly we need a --force or something).

I'll look into doing something more here.

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
Tools/Scripts/update-w3c-deps:46: if status and not 'nothing to commit, working
directory clean' in status:
Yeah, will look into doing something stronger here as well. The waffles are the
same flavor :).

[Dirk Pranke, 2014-03-10 21:19:27]

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
File Tools/Scripts/update-w3c-deps (right):

https://codereview.chromium.org/148173016/diff/20001/Tools/Scripts/update-w3c...
Tools/Scripts/update-w3c-deps:46: if status and not 'nothing to commit, working
directory clean' in status:
On 2014/02/08 01:04:31, Dirk Pranke wrote:
> Yeah, will look into doing something stronger here as well. The waffles are
the
> same flavor :).

Turns out that 'git diff --quiet commitish' probably does the best thing here
(no output, but exit code of 1 indicates that there is a diff), so I'll change
that here and above.

[Dirk Pranke, 2014-03-12 23:25:47]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-03-12 23:25:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dpranke@chromium.org/148173016/120001

[commit-bot: I haz the power, 2014-03-12 23:27:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-12 23:27:03]

Try jobs failed on following builders:
  tryserver.chromium on mac_blink_rel

[Dirk Pranke, 2014-03-13 00:26:42]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-03-13 00:26:46]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dpranke@chromium.org/148173016/120001

[commit-bot: I haz the power, 2014-03-13 02:49:55]

Change committed as 169082