Remove dependency on cc::TestNowSource from scheduler code

Remove dependency on cc::TestNowSource from scheduler code

BUG=478736
R=skyostil@chromium.org

Committed: https://crrev.com/a3635a7de383a295e52a35c1ae4e72aecab14d77
Cr-Commit-Position: refs/heads/master@{#326006}

[Sami, 2015-04-20 18:38:36]

lgtm, thanks for fixing this!

https://codereview.chromium.org/1098033002/diff/1/content/child/scheduler/tas...
File content/child/scheduler/task_queue_manager.h (right):

https://codereview.chromium.org/1098033002/diff/1/content/child/scheduler/tas...
content/child/scheduler/task_queue_manager.h:125: void
SetTimeSourceForTesting(scoped_ptr<TimeSource> time_source);
Passing the ownership here is a little odd since you then can't easily use the
same TimeSource with the TaskQueueManager and the Scheduler without having a
forwarding wrapper. However since this is just for tests I think this works fine
too.

[jochen (gone - plz use gerrit), 2015-04-20 18:43:58]

The CQ bit was checked by jochen@chromium.org

[jochen (gone - plz use gerrit), 2015-04-20 18:43:59]

The patchset sent to the CQ was uploaded after l-g-t-m from
skyostil@chromium.org
Link to the patchset: https://codereview.chromium.org/1098033002/#ps20001
(title: "updates")

[commit-bot: I haz the power, 2015-04-20 18:44:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1098033002/20001

[commit-bot: I haz the power, 2015-04-20 21:01:31]

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

[commit-bot: I haz the power, 2015-04-20 21:01:32]

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

[jochen (gone - plz use gerrit), 2015-04-21 08:15:36]

The CQ bit was checked by jochen@chromium.org

[jochen (gone - plz use gerrit), 2015-04-21 08:15:37]

The patchset sent to the CQ was uploaded after l-g-t-m from
skyostil@chromium.org
Link to the patchset: https://codereview.chromium.org/1098033002/#ps40001
(title: "updates")

[commit-bot: I haz the power, 2015-04-21 08:16:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1098033002/40001

[commit-bot: I haz the power, 2015-04-21 10:29:00]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-04-21 10:29:53]

Patchset 3 (id:??) landed as
https://crrev.com/a3635a7de383a295e52a35c1ae4e72aecab14d77
Cr-Commit-Position: refs/heads/master@{#326006}