Fix trivial lint errors in FileRecorder and FilePlayer

Fix trivial lint errors in FileRecorder and FilePlayer

Mostly, it's about replacing mutable reference arguments with pointer
arguments, and replacing C style casts with C++ style casts.

Committed: https://crrev.com/4ec01d9c9d77de437e953fa69f802aa42b98e630
Cr-Commit-Position: refs/heads/master@{#13849}

[kwiberg-webrtc, 2016-06-09 08:22:46]

Patchset #1 (id:1) has been deleted

[kwiberg-webrtc, 2016-08-17 10:48:23]

Patchset #1 (id:20001) has been deleted

[kwiberg-webrtc, 2016-08-17 13:14:16]

kwiberg@webrtc.org changed reviewers:
+ ossu@webrtc.org

[ossu, 2016-08-19 13:28:10]

lgtm

[kwiberg-webrtc, 2016-08-19 13:29:56]

The CQ bit was checked by kwiberg@webrtc.org

[commit-bot: I haz the power, 2016-08-19 13:30:09]

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, 2016-08-19 15:30:44]

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

[commit-bot: I haz the power, 2016-08-19 15:30:45]

Try jobs failed on following builders:
  android_arm64_rel on master.tryserver.webrtc (JOB_TIMED_OUT, no build URL)

[kwiberg-webrtc, 2016-08-22 13:24:38]

The CQ bit was checked by kwiberg@webrtc.org

[commit-bot: I haz the power, 2016-08-22 13:24:48]

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, 2016-08-22 15:43:58]

Committed patchset #1 (id:40001)

[commit-bot: I haz the power, 2016-08-22 15:44:03]

Description was changed from

==========
Fix trivial lint errors in FileRecorder and FilePlayer

Mostly, it's about replacing mutable reference arguments with pointer
arguments, and replacing C style casts with C++ style casts.
==========

to

==========
Fix trivial lint errors in FileRecorder and FilePlayer

Mostly, it's about replacing mutable reference arguments with pointer
arguments, and replacing C style casts with C++ style casts.

Committed: https://crrev.com/4ec01d9c9d77de437e953fa69f802aa42b98e630
Cr-Commit-Position: refs/heads/master@{#13849}
==========

[commit-bot: I haz the power, 2016-08-22 15:44:04]

Patchset 1 (id:??) landed as
https://crrev.com/4ec01d9c9d77de437e953fa69f802aa42b98e630
Cr-Commit-Position: refs/heads/master@{#13849}