Fix typos in JS types

Fix typos in JS types

This CL fixes typos in JS types introduced by CL 1006553002.

BUG=460428
TEST=None

TBR=stevenjb

Committed: https://crrev.com/a4e6460a415d0d2568c59ef1efdb9998e24a0e97
Cr-Commit-Position: refs/heads/master@{#321323}

[bartfab (slow), 2015-03-19 06:54:16]

The CQ bit was checked by bartfab@chromium.org

[commit-bot: I haz the power, 2015-03-19 06:54:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1016103003/20001

[commit-bot: I haz the power, 2015-03-19 08:23:27]

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

[commit-bot: I haz the power, 2015-03-19 08:23:27]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[bartfab (slow), 2015-03-19 08:32:05]

The CQ bit was checked by bartfab@chromium.org

[commit-bot: I haz the power, 2015-03-19 08:32:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1016103003/20001

[commit-bot: I haz the power, 2015-03-19 09:55:10]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-19 09:55:36]

Patchset 2 (id:??) landed as
https://crrev.com/a4e6460a415d0d2568c59ef1efdb9998e24a0e97
Cr-Commit-Position: refs/heads/master@{#321323}