Reland of New statistics interface for APM

Original CL: https://codereview.webrtc.org/2433153003/, commit 8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit 48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure virtual.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org

Committed: https://crrev.com/3e9a53760101a5b14d771ee1152b2988685d630e
Cr-Commit-Position: refs/heads/master@{#14827}

[ivoc, 2016-10-28 13:42:13]

Description was changed from

==========
Initial CL.

BUG=webrtc:6525
==========

to

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure.

BUG=webrtc:6525
==========

[ivoc, 2016-10-28 13:43:07]

ivoc@webrtc.org changed reviewers:
+ peah@webrtc.org, solenberg@webrtc.org

[ivoc, 2016-10-28 13:45:54]

Description was changed from

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure.

BUG=webrtc:6525
==========

to

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org
==========

[ivoc, 2016-10-28 13:49:09]

Description was changed from

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org
==========

to

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure virtual.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org
==========

[ivoc, 2016-10-28 13:49:32]

The CQ bit was checked by ivoc@webrtc.org

[commit-bot: I haz the power, 2016-10-28 13:49:35]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2016-10-28 13:54:04]

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

[commit-bot: I haz the power, 2016-10-28 13:54:05]

Try jobs failed on following builders:
  ios64_sim_dbg on master.tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/ios64_sim_dbg/builds/11980)
  ios_dbg on master.tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/ios_dbg/builds/19546)

[ivoc, 2016-10-28 14:32:13]

The CQ bit was checked by ivoc@webrtc.org

[commit-bot: I haz the power, 2016-10-28 14:32:20]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2016-10-28 14:55:35]

Description was changed from

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure virtual.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org
==========

to

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure virtual.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org
==========

[commit-bot: I haz the power, 2016-10-28 14:55:36]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-10-28 14:55:43]

Description was changed from

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure virtual.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org
==========

to

==========
Original CL: https://codereview.webrtc.org/2433153003/, commit
8b8d3e4c30e8ea3846b58dfd36d1fd35a7799df4.
Revert CL: https://codereview.webrtc.org/2456333002/, commit
48dfab5c58119a4e65c52506ed55f8de79725bcf.

The new function on the APM interface is no longer pure virtual.

BUG=webrtc:6525
TBR=solenberg@webrtc.org,peah@webrtc.org

Committed: https://crrev.com/3e9a53760101a5b14d771ee1152b2988685d630e
Cr-Commit-Position: refs/heads/master@{#14827}
==========

[commit-bot: I haz the power, 2016-10-28 14:55:44]

Patchset 3 (id:??) landed as
https://crrev.com/3e9a53760101a5b14d771ee1152b2988685d630e
Cr-Commit-Position: refs/heads/master@{#14827}