Add setIndexedDBClientCreateFunction() explanatory comment.

Add setIndexedDBClientCreateFunction() explanatory comment.

Follow up changes in r385772 and r385733 with a comment to
try to explain why update atomicity matters here.

R=
BUG=598551, 599011
NOTRY=true

Committed: https://crrev.com/4fa5dd8ee1e6f6c8719935152f3b48f82626d595
Cr-Commit-Position: refs/heads/master@{#386000}

[sof, 2016-04-08 05:39:35]

sigbjornf@opera.com changed reviewers:
+ haraken@chromium.org

[sof, 2016-04-08 05:39:36]

To try to avoid unnecessary head scratching for whoever looks at this code
next..

[haraken, 2016-04-08 05:45:33]

LGTM

[sof, 2016-04-08 05:50:13]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2016-04-08 05:50:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1862223005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1862223005/1

[commit-bot: I haz the power, 2016-04-08 05:55:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-08 05:56:42]

Description was changed from

==========
Add setIndexedDBClientCreateFunction() explanatory comment.

Follow up changes in r385772 and r385733 with a comment to
try to explain why update atomicity matters here.

R=
BUG=598551, 599011
NOTRY=true
==========

to

==========
Add setIndexedDBClientCreateFunction() explanatory comment.

Follow up changes in r385772 and r385733 with a comment to
try to explain why update atomicity matters here.

R=
BUG=598551, 599011
NOTRY=true

Committed: https://crrev.com/4fa5dd8ee1e6f6c8719935152f3b48f82626d595
Cr-Commit-Position: refs/heads/master@{#386000}
==========

[commit-bot: I haz the power, 2016-04-08 05:56:43]

Patchset 1 (id:??) landed as
https://crrev.com/4fa5dd8ee1e6f6c8719935152f3b48f82626d595
Cr-Commit-Position: refs/heads/master@{#386000}