Add ENABLE_MEDIA_ROUTER define

Add ENABLE_MEDIA_ROUTER define to builds other than Android and iOS.

BUG=461815
Committed: https://crrev.com/e62587c04a6a1732e61bff63fda0504d578fb391
Cr-Commit-Position: refs/heads/master@{#324177}

[mark a. foltz, 2015-04-07 20:07:06]

mfoltz@chromium.org changed reviewers:
+ imcheng@chromium.org, thakis@chromium.org

[Nico, 2015-04-07 20:16:04]

Do you need this in the .gn file too?

[Nico, 2015-04-07 20:16:04]

Do you need this in the .gn file too?

[mark a. foltz, 2015-04-07 20:29:13]

On 2015/04/07 20:16:04, Nico wrote:
> Do you need this in the .gn file too?

Done.

[Nico, 2015-04-07 20:32:36]

lgtm

https://codereview.chromium.org/1069063002/diff/20001/build/config/BUILD.gn
File build/config/BUILD.gn (right):

https://codereview.chromium.org/1069063002/diff/20001/build/config/BUILD.gn#n...
build/config/BUILD.gn:39: # define, but anything that doesn't depend on X11
doesn't see it.
Is this feasible for your feature? Or do you need the define in every single
translation unit?

[mark a. foltz, 2015-04-07 21:27:05]

https://codereview.chromium.org/1069063002/diff/20001/build/config/BUILD.gn
File build/config/BUILD.gn (right):

https://codereview.chromium.org/1069063002/diff/20001/build/config/BUILD.gn#n...
build/config/BUILD.gn:39: # define, but anything that doesn't depend on X11
doesn't see it.
On 2015/04/07 20:32:35, Nico wrote:
> Is this feasible for your feature? Or do you need the define in every single
> translation unit?

It looks feasible.  There are probably a half dozen .gn files that would need
the define declared, so I reverted this declaration.

I didn't follow the comment about using a "meta-target." It seems like that
would add the define to all dependents, even if there were no #ifdef that used
it.

[imcheng, 2015-04-07 23:42:13]

lgtm

[mark a. foltz, 2015-04-07 23:58:36]

The CQ bit was checked by mfoltz@chromium.org

[mark a. foltz, 2015-04-07 23:58:36]

The patchset sent to the CQ was uploaded after l-g-t-m from thakis@chromium.org
Link to the patchset: https://codereview.chromium.org/1069063002/#ps40001
(title: "Revert BUILD.gn")

[commit-bot: I haz the power, 2015-04-07 23:59:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1069063002/40001

[commit-bot: I haz the power, 2015-04-08 02:32:30]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-04-08 02:33:21]

Patchset 3 (id:??) landed as
https://crrev.com/e62587c04a6a1732e61bff63fda0504d578fb391
Cr-Commit-Position: refs/heads/master@{#324177}