Clamp number of downscales in QualityScaler.

Clamp number of downscales in QualityScaler.

Fixes bug where QualityScaler would be stuck "way below" QVGA (due to
downscale_shift_) even though it would never scale below QVGA. Also
fixes issue where samples would be cleared when either staying at max
resolution or going below QVGA even though no action happened.

BUG=
R=glaznev@webrtc.org

Committed: https://crrev.com/919288f6ba4ac2112c616c877273e84374904da9
Cr-Commit-Position: refs/heads/master@{#12691}

[pbos-webrtc, 2016-05-11 21:13:02]

PTAL

[pbos-webrtc, 2016-05-11 21:13:07]

The CQ bit was checked by pbos@webrtc.org to run a CQ dry run

[commit-bot: I haz the power, 2016-05-11 21:13:18]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1971693003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1971693003/1

[commit-bot: I haz the power, 2016-05-11 21:49:09]

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

[commit-bot: I haz the power, 2016-05-11 21:49:10]

Dry run: Try jobs failed on following builders:
  linux_msan on tryserver.webrtc (JOB_FAILED,
http://build.chromium.org/p/tryserver.webrtc/builders/linux_msan/builds/9998)

[pbos-webrtc, 2016-05-11 22:08:08]

zero out initial resolution

[pbos-webrtc, 2016-05-11 22:17:14]

this should've covered the bot failure

[AlexG, 2016-05-11 23:51:38]

lgtm

[pbos-webrtc, 2016-05-12 00:17:58]

Description was changed from

==========
Clamp number of downscales in QualityScaler.

Fixes bug where QualityScaler would be stuck "way below" QVGA (due to
downscale_shift_) even though it would never scale below QVGA. Also
fixes issue where samples would be cleared when either staying at max
resolution or going below QVGA even though no action happened.

BUG=
R=glaznev@webrtc.org
==========

to

==========
Clamp number of downscales in QualityScaler.

Fixes bug where QualityScaler would be stuck "way below" QVGA (due to
downscale_shift_) even though it would never scale below QVGA. Also
fixes issue where samples would be cleared when either staying at max
resolution or going below QVGA even though no action happened.

BUG=
R=glaznev@webrtc.org

Committed:
https://chromium.googlesource.com/external/webrtc/+/919288f6ba4ac2112c616c877...
==========

[pbos-webrtc, 2016-05-12 00:18:00]

Committed patchset #2 (id:20001) manually as
919288f6ba4ac2112c616c877273e84374904da9 (presubmit successful).

[commit-bot: I haz the power, 2016-05-12 00:18:01]

Description was changed from

==========
Clamp number of downscales in QualityScaler.

Fixes bug where QualityScaler would be stuck "way below" QVGA (due to
downscale_shift_) even though it would never scale below QVGA. Also
fixes issue where samples would be cleared when either staying at max
resolution or going below QVGA even though no action happened.

BUG=
R=glaznev@webrtc.org

Committed:
https://chromium.googlesource.com/external/webrtc/+/919288f6ba4ac2112c616c877...
==========

to

==========
Clamp number of downscales in QualityScaler.

Fixes bug where QualityScaler would be stuck "way below" QVGA (due to
downscale_shift_) even though it would never scale below QVGA. Also
fixes issue where samples would be cleared when either staying at max
resolution or going below QVGA even though no action happened.

BUG=
R=glaznev@webrtc.org

Committed: https://crrev.com/919288f6ba4ac2112c616c877273e84374904da9
Cr-Commit-Position: refs/heads/master@{#12691}
==========