Revert of Update third_party/checkstyle to 7.6.1

Revert of Update third_party/checkstyle to 7.6.1 (patchset #2 id:40001 of https://codereview.chromium.org/2799303003/ )

Reason for revert:
Breaking trybots

Original issue's description:
> Update third_party/checkstyle to 7.6.1
> 
> This CL updates third_party/checkstyle to 7.6.1 so checkstyle would
> work with Java 8 lambda features.
> 
> BUG=703238
> 
> Review-Url: https://codereview.chromium.org/2799303003
> Cr-Commit-Position: refs/heads/master@{#462968}
> Committed: https://chromium.googlesource.com/chromium/src/+/dbce02f63421f7d446d6ef317b456f6ae911f63b

TBR=agrieve@chromium.org,nyquist@chromium.org,jbudorick@chromium.org,klobag@chromium.org,jbudorick@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=703238

[F, 2017-04-07 20:13:18]

The CQ bit was checked by zpeng@chromium.org

[F, 2017-04-07 20:13:18]

Created Revert of Update third_party/checkstyle to 7.6.1

[commit-bot: I haz the power, 2017-04-07 20:13:48]

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, 2017-04-07 20:19:26]

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

[commit-bot: I haz the power, 2017-04-07 20:19:33]

Failed to request the patch to try. Please note that binary files are still
unsupported at the moment, this is being worked on.

This could be a Rietveld flake (see http://crbug.com/401833), so if this CL has
no binary files, please re-check commit box.
Thanks for your patience.

Transient error: Can't process patch for file
third_party/checkstyle/checkstyle-6.5-all.jar.
Binary file is empty. Maybe the file wasn't uploaded in the first place?

[F, 2017-04-07 20:24:16]

The CQ bit was checked by zpeng@chromium.org

[commit-bot: I haz the power, 2017-04-07 20:25:02]

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, 2017-04-07 20:28:13]

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

[commit-bot: I haz the power, 2017-04-07 20:28:14]

Failed to request the patch to try. Please note that binary files are still
unsupported at the moment, this is being worked on.

This could be a Rietveld flake (see http://crbug.com/401833), so if this CL has
no binary files, please re-check commit box.
Thanks for your patience.

Transient error: Can't process patch for file
third_party/checkstyle/checkstyle-6.5-all.jar.
Binary file is empty. Maybe the file wasn't uploaded in the first place?

[Alexei Svitkine (slow), 2017-04-07 22:28:48]

asvitkine@chromium.org changed reviewers:
+ asvitkine@chromium.org

[Alexei Svitkine (slow), 2017-04-07 22:28:49]

I was able to revert via https://codereview.chromium.org/2807753003

Did a local git revert on the original commit hash, then committed that locally,
uploaded to codereview and did a git cl land.