Add enable_media_router check to GN based grit targets.

Add enable_media_router check to GN based grit targets.

Originally, <if expr="enable_media_router"> was not picked up by a .grd file. I traced that to grit_rule.gni and added a check there.

Committed: https://crrev.com/2be1ebd65b769821ad36e6cff2d47bda574c00bb
Cr-Commit-Position: refs/heads/master@{#326598}

[apacible, 2015-04-22 02:50:00]

Patchset #1 (id:1) has been deleted

[apacible, 2015-04-22 16:22:31]

Patchset #1 (id:20001) has been deleted

[apacible, 2015-04-22 17:20:41]

apacible@chromium.org changed reviewers:
+ brettw@chromium.org

[apacible, 2015-04-22 17:26:10]

PTAL, thanks!

[apacible, 2015-04-23 18:00:24]

apacible@chromium.org changed reviewers:
+ cjhopman@chromium.org

[apacible, 2015-04-23 18:07:02]

+cjhopman

[cjhopman, 2015-04-23 18:08:03]

lgtm

[apacible, 2015-04-23 18:08:51]

The CQ bit was checked by apacible@chromium.org

[commit-bot: I haz the power, 2015-04-23 18:10:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1104443002/40001

[commit-bot: I haz the power, 2015-04-23 18:57:20]

Committed patchset #1 (id:40001)

[commit-bot: I haz the power, 2015-04-23 18:58:14]

Patchset 1 (id:??) landed as
https://crrev.com/2be1ebd65b769821ad36e6cff2d47bda574c00bb
Cr-Commit-Position: refs/heads/master@{#326598}