Add documentation to the RendererConfig interface.

Add documentation to the RendererConfig interface.

Whoops, forgot to add this before submitting the last patch.

BUG=410451
TEST=none

Committed: https://crrev.com/36c378b881b6a481294800ca1de5390a6136059d
Cr-Commit-Position: refs/heads/master@{#301971}

[DaleCurtis, 2014-10-29 20:59:19]

dalecurtis@chromium.org changed reviewers:
+ xhwang@chromium.org

[DaleCurtis, 2014-10-29 20:59:19]

Forgot to add these.

[xhwang, 2014-10-29 21:17:51]

lgtm

[DaleCurtis, 2014-10-29 21:18:37]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2014-10-29 21:20:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/645373005/1

[commit-bot: I haz the power, 2014-10-29 21:54:59]

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

[commit-bot: I haz the power, 2014-10-29 21:55:00]

Try jobs failed on following builders:
  win_chromium_compile_dbg on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_comp...)

[DaleCurtis, 2014-10-29 22:48:31]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2014-10-29 22:50:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/645373005/1

[commit-bot: I haz the power, 2014-10-29 23:16:32]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-29 23:17:17]

Patchset 1 (id:??) landed as
https://crrev.com/36c378b881b6a481294800ca1de5390a6136059d
Cr-Commit-Position: refs/heads/master@{#301971}