Fix native_viewport CommandLine; enable window_manager_apptests.

Fix native_viewport CommandLine; enable window_manager_apptests.

Update the native_viewport CommandLine usage pattern.
(codereview.chromium.org/1057603003 removed per-app args)

Re-enable window_manager_apptests with test and headless flags.
(our FYI waterfall: http://build.chromium.org/p/chromium.mojo/console)

BUG=480040
TEST=Tests pass on the waterfall.
R=sky@chromium.org
TBR=jochen@chromium.org

Committed: https://crrev.com/4795dc0ed1c25fafc1e35e34614e4294d3811754
Cr-Commit-Position: refs/heads/master@{#327139}

[msw, 2015-04-27 20:36:15]

Hey Scott, please take a look; thanks!

[sky, 2015-04-27 21:06:03]

LGTM

[msw, 2015-04-27 21:18:21]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2015-04-27 21:19:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1107133002/40001

[commit-bot: I haz the power, 2015-04-27 21:30:32]

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

[commit-bot: I haz the power, 2015-04-27 21:30:33]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[msw, 2015-04-27 21:34:20]

msw@chromium.org changed reviewers:
+ jochen@chromium.org

[msw, 2015-04-27 21:34:33]

TBR'ing jochen@chromium.org for components/OWNERS

[msw, 2015-04-27 21:34:39]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2015-04-27 21:34:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1107133002/40001

[commit-bot: I haz the power, 2015-04-27 21:39:22]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-04-27 21:40:55]

Patchset 3 (id:??) landed as
https://crrev.com/4795dc0ed1c25fafc1e35e34614e4294d3811754
Cr-Commit-Position: refs/heads/master@{#327139}