Fix webkit-patch --help.

Fix webkit-patch --help.

I believe that after http://crrev.com/2276713002, invoking webkit-patch
with --help rather than help was broken.

When `webkit-patch help` is invoked, the codepath that's used goes through
the execute method of HelpCommand, and the _tool attribute is set, so it
worked.

But when --help is passed, a different codepath is used, that goes through
optparse which directly uses HelpCommand.help_epilog and the _tool attribute
was never set.

This CL fixes this case by setting the _tool attribute in the constructor
of HelpCommand.

Committed: https://crrev.com/3d1a19a2bd38572c918334f68d83b36989ea557b
Cr-Commit-Position: refs/heads/master@{#423017}

[qyearsley, 2016-10-04 21:09:14]

qyearsley@chromium.org changed reviewers:
+ dpranke@chromium.org, jeffcarp@chromium.org

[jeffcarp, 2016-10-04 22:54:44]

lgtm

[qyearsley, 2016-10-04 23:25:15]

The CQ bit was checked by qyearsley@chromium.org

[commit-bot: I haz the power, 2016-10-04 23:25:30]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-05 00:25:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-05 00:31:06]

Description was changed from

==========
Fix webkit-patch --help.

I believe that after http://crrev.com/2276713002, invoking webkit-patch
with --help rather than help was broken.


When `webkit-patch help` is invoked, the codepath that's used goes through
the execute method of HelpCommand, and the _tool attribute is set, so it
worked.

But when --help is passed, a different codepath is used, that goes through
optparse which directly uses HelpCommand.help_epilog and the _tool attribute
was never set.

This CL fixes this case by setting the _tool attribute in the constructor
of HelpCommand.
==========

to

==========
Fix webkit-patch --help.

I believe that after http://crrev.com/2276713002, invoking webkit-patch
with --help rather than help was broken.

When `webkit-patch help` is invoked, the codepath that's used goes through
the execute method of HelpCommand, and the _tool attribute is set, so it
worked.

But when --help is passed, a different codepath is used, that goes through
optparse which directly uses HelpCommand.help_epilog and the _tool attribute
was never set.

This CL fixes this case by setting the _tool attribute in the constructor
of HelpCommand.

Committed: https://crrev.com/3d1a19a2bd38572c918334f68d83b36989ea557b
Cr-Commit-Position: refs/heads/master@{#423017}
==========

[commit-bot: I haz the power, 2016-10-05 00:31:07]

Patchset 1 (id:??) landed as
https://crrev.com/3d1a19a2bd38572c918334f68d83b36989ea557b
Cr-Commit-Position: refs/heads/master@{#423017}