Fix accumulation error with front_timestamp, move test only code.

Fix accumulation error with front_timestamp, move test only code.

DCHECKs showed the front and back timestamps drifting by a few
microseconds, likely due to repeated accumulation errors (since
we're doing double*int64 -> repeated addition).

I also cleaned up some code which was only used for tests to
avoid accumulating unnused values in production.

No new tests since code gen will affect the accumulation errors.

BUG=481640
TEST=existing tests all pass.

Committed: https://crrev.com/b53d11d580755daf0041232d5e094807d34f67ab
Cr-Commit-Position: refs/heads/master@{#338726}

[DaleCurtis, 2015-07-13 23:13:29]

dalecurtis@chromium.org changed reviewers:
+ jrummell@chromium.org, xhwang@chromium.org

[DaleCurtis, 2015-07-13 23:13:29]

Finally tracked down that dcheck :)

[xhwang, 2015-07-14 06:17:25]

Great find! LGTM

[jrummell, 2015-07-14 17:32:22]

lgtm

https://codereview.chromium.org/1233963002/diff/1/media/filters/audio_clock_u...
File media/filters/audio_clock_unittest.cc (right):

https://codereview.chromium.org/1233963002/diff/1/media/filters/audio_clock_u...
media/filters/audio_clock_unittest.cc:63: base::TimeDelta
contiguous_audio_data_buffered_at_same_rate_;
nit: I don't see these 2 values used anywhere in the changes. Moved from
audio_clock.h and then not used?

[DaleCurtis, 2015-07-14 17:33:59]

Thanks for review!

https://codereview.chromium.org/1233963002/diff/1/media/filters/audio_clock_u...
File media/filters/audio_clock_unittest.cc (right):

https://codereview.chromium.org/1233963002/diff/1/media/filters/audio_clock_u...
media/filters/audio_clock_unittest.cc:63: base::TimeDelta
contiguous_audio_data_buffered_at_same_rate_;
On 2015/07/14 17:32:22, jrummell wrote:
> nit: I don't see these 2 values used anywhere in the changes. Moved from
> audio_clock.h and then not used?

Whoops, yeah moved and unused. Removed.

[DaleCurtis, 2015-07-14 17:34:10]

The CQ bit was checked by dalecurtis@chromium.org

[DaleCurtis, 2015-07-14 17:34:10]

The patchset sent to the CQ was uploaded after l-g-t-m from
jrummell@chromium.org, xhwang@chromium.org
Link to the patchset: https://codereview.chromium.org/1233963002/#ps20001
(title: "Remove unused vars.")

[commit-bot: I haz the power, 2015-07-14 17:35:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1233963002/20001

[commit-bot: I haz the power, 2015-07-14 17:57:24]

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

[commit-bot: I haz the power, 2015-07-14 17:57:25]

Try jobs failed on following builders:
  win8_chromium_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/...)

[DaleCurtis, 2015-07-14 18:59:03]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2015-07-14 18:59:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1233963002/20001

[commit-bot: I haz the power, 2015-07-14 19:20:28]

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

[commit-bot: I haz the power, 2015-07-14 19:20:29]

Try jobs failed on following builders:
  win8_chromium_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/...)

[DaleCurtis, 2015-07-14 19:43:36]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2015-07-14 19:44:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1233963002/20001

[commit-bot: I haz the power, 2015-07-14 20:06:19]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-14 20:07:23]

Patchset 2 (id:??) landed as
https://crrev.com/b53d11d580755daf0041232d5e094807d34f67ab
Cr-Commit-Position: refs/heads/master@{#338726}