Add comments in UseCounter.h for M58 and M59 branch cutoffs

Add comments in UseCounter.h for M58 and M59 branch cutoffs

M58 and M59 branches were versioned in the following commits:
58 version increment: 2b7c19d3
59 version increment: 7ee0c5a1

UseCounter.h can be seen at these versions as follows:
git show 2b7c19d3:third_party/WebKit/Source/core/frame/UseCounter.h
git show 7ee0c5a1:third_party/WebKit/Source/core/frame/UseCounter.h

Review-Url: https://codereview.chromium.org/2824943003
Cr-Commit-Position: refs/heads/master@{#465160}
Committed: https://chromium.googlesource.com/chromium/src/+/313a30da6762cab7c0d9cd958c6119fd3768afa1

[Timothy Loh, 2017-04-18 04:00:13]

The CQ bit was checked by timloh@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-18 04:00:27]

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

[Timothy Loh, 2017-04-18 04:01:51]

timloh@chromium.org changed reviewers:
+ alancutter@chromium.org

[commit-bot: I haz the power, 2017-04-18 05:46:26]

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

[commit-bot: I haz the power, 2017-04-18 05:46:27]

Dry run: This issue passed the CQ dry run.

[alancutter (OOO until 2018), 2017-04-18 06:50:18]

lgtm

[Timothy Loh, 2017-04-18 06:50:46]

The CQ bit was checked by timloh@chromium.org

[commit-bot: I haz the power, 2017-04-18 06:51:14]

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, 2017-04-18 06:54:52]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1492498246401430, "parent_rev":
"604168304f0d95d0fbaf3775b2bd4e1a3ab5dab4", "commit_rev":
"313a30da6762cab7c0d9cd958c6119fd3768afa1"}

[commit-bot: I haz the power, 2017-04-18 06:55:01]

Description was changed from

==========
Add comments in UseCounter.h for M58 and M59 branch cutoffs

M58 and M59 branches were versioned in the following commits:
58 version increment: 2b7c19d3
59 version increment: 7ee0c5a1

UseCounter.h can be seen at these versions as follows:
git show 2b7c19d3:third_party/WebKit/Source/core/frame/UseCounter.h
git show 7ee0c5a1:third_party/WebKit/Source/core/frame/UseCounter.h
==========

to

==========
Add comments in UseCounter.h for M58 and M59 branch cutoffs

M58 and M59 branches were versioned in the following commits:
58 version increment: 2b7c19d3
59 version increment: 7ee0c5a1

UseCounter.h can be seen at these versions as follows:
git show 2b7c19d3:third_party/WebKit/Source/core/frame/UseCounter.h
git show 7ee0c5a1:third_party/WebKit/Source/core/frame/UseCounter.h

Review-Url: https://codereview.chromium.org/2824943003
Cr-Commit-Position: refs/heads/master@{#465160}
Committed:
https://chromium.googlesource.com/chromium/src/+/313a30da6762cab7c0d9cd958c61...
==========

[commit-bot: I haz the power, 2017-04-18 06:55:02]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/313a30da6762cab7c0d9cd958c61...