extensions: don't animate options dialog when loading.

extensions: don't animate options dialog when loading.

Transitions are disabled while loading, so animations should be as well.

This happens when chrome://extensions/?options=<id> is navigated to,
which shows the dialog immediately.

R=kalman@chromium.org
BUG=none
TEST=load chrome://extensions/?options=<extension_id> and look for
     needless animation

Committed: https://crrev.com/49c190353a2c6c95178e70b517770fd837109251
Cr-Commit-Position: refs/heads/master@{#314649}

[Dan Beam, 2015-02-04 19:09:30]

https://codereview.chromium.org/896283003/diff/1/chrome/browser/resources/ext...
File chrome/browser/resources/extensions/extension_options_overlay.js (right):

https://codereview.chromium.org/896283003/diff/1/chrome/browser/resources/ext...
chrome/browser/resources/extensions/extension_options_overlay.js:124: var
loading = document.documentElement.classlist.contains('loading');
note: this doesn't work all that well but will when hcarmona@ or I fix the
constant rebuild issues

[not at google - send to devlin, 2015-02-04 20:38:04]

lgtm

[Dan Beam, 2015-02-04 21:06:54]

New patchsets have been uploaded after l-g-t-m from kalman@chromium.org

[Dan Beam, 2015-02-04 21:07:17]

The CQ bit was checked by dbeam@chromium.org

[commit-bot: I haz the power, 2015-02-04 21:08:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/896283003/20001

[commit-bot: I haz the power, 2015-02-04 21:56:20]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-04 21:57:32]

Patchset 2 (id:??) landed as
https://crrev.com/49c190353a2c6c95178e70b517770fd837109251
Cr-Commit-Position: refs/heads/master@{#314649}