First stage of launch for embedded options pages. With this patch, extensions

First stage of launch for embedded options pages. With this patch, extensions
are allowed to opt-in to having embedded options pages and/or chrome style.

The flag --enable-embedded-extension-options makes the default for embedding
options pages true unless extensions opt-out. This is still useful for
development.

BUG=414920
R=rockot@chromium.org

Committed: https://crrev.com/9807701d4c6789b9df38a9a33ca28ca4de2861c5
Cr-Commit-Position: refs/heads/master@{#300190}

[Ken Rockot(use gerrit already), 2014-10-17 18:08:01]

lgtm

[not at google - send to devlin, 2014-10-17 18:09:13]

The CQ bit was checked by kalman@chromium.org

[commit-bot: I haz the power, 2014-10-17 18:10:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/667453003/1

[commit-bot: I haz the power, 2014-10-18 00:50:12]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-18 00:51:04]

Patchset 1 (id:??) landed as
https://crrev.com/9807701d4c6789b9df38a9a33ca28ca4de2861c5
Cr-Commit-Position: refs/heads/master@{#300190}