[json] detect overflow sooner when serializing large sparse array.

[json] detect overflow sooner when serializing large sparse array.

R=mlippautz@chromium.org, yukishiino@chromium.org
BUG=chromium:617649
Committed: https://crrev.com/19067e5fbc3da97f87a4b430a1b589529723cdbd
Cr-Commit-Position: refs/heads/master@{#36961}

[Yuki, 2016-06-14 10:20:08]

LGTM from my perspective.

[Yang, 2016-06-14 11:04:26]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2016-06-14 11:04:27]

The patchset sent to the CQ was uploaded after l-g-t-m from
yukishiino@chromium.org
Link to the patchset: https://codereview.chromium.org/2069563002/#ps20001
(title: "check string length upfront")

[commit-bot: I haz the power, 2016-06-14 11:04:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2069563002/20001

[commit-bot: I haz the power, 2016-06-14 11:34:26]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-06-14 11:37:13]

Description was changed from

==========
[json] detect overflow sooner when serializing large sparse array.

R=mlippautz@chromium.org, yukishiino@chromium.org
BUG=chromium:617649
==========

to

==========
[json] detect overflow sooner when serializing large sparse array.

R=mlippautz@chromium.org, yukishiino@chromium.org
BUG=chromium:617649

Committed: https://crrev.com/19067e5fbc3da97f87a4b430a1b589529723cdbd
Cr-Commit-Position: refs/heads/master@{#36961}
==========

[commit-bot: I haz the power, 2016-06-14 11:37:14]

Patchset 2 (id:??) landed as
https://crrev.com/19067e5fbc3da97f87a4b430a1b589529723cdbd
Cr-Commit-Position: refs/heads/master@{#36961}