webkit: Cleanup - make everything private as much as possible.

webkit: Cleanup - make everything private as much as possible.

This helps to reduce the public surface of this API and makes clear what can
be accessed by the clients/consumers of this API.

BUG=338338
TEST=None
R=piman@chromium.org

Committed: https://crrev.com/9c951cf71dcd32f75ccd0c68bd342a2eb434d700
Cr-Commit-Position: refs/heads/master@{#311976}

[tfarina, 2015-01-16 20:08:18]

PTAL

[piman, 2015-01-16 21:38:04]

lgtm

[tfarina, 2015-01-16 22:29:43]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2015-01-16 22:30:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/858643002/60001

[commit-bot: I haz the power, 2015-01-16 23:27:25]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-01-16 23:28:13]

Patchset 4 (id:??) landed as
https://crrev.com/9c951cf71dcd32f75ccd0c68bd342a2eb434d700
Cr-Commit-Position: refs/heads/master@{#311976}