Revert of Adding support for simulcast and spatial layers into VideoQualityTest

Revert of Adding support for simulcast and spatial layers into VideoQualityTest (patchset #10 id:180001 of https://codereview.webrtc.org/1353263005/ )

Reason for revert:
Temporarily reverting as this causes some issues with perf tests. Especially tests with packet loss no longer works.

Original issue's description:
> Adding support for simulcast and spatial layers into VideoQualityTest
>
> The CL includes several changes:
> - Adding flags describing the streams and spatial layers.
> - Reorganizing the order of the flags, to make them easier to maintain.
> - Adding a member .params_ to VideoQualityAnalyzer.
>     (instead of passing it to every member function manually)
> - Updating VideoAnalyzer to support simulcast.
>     (select appropriate ssrc and fix timestamps which are sometimes increased by 1)
> - VP9EncoderImpl already had code for automatic calculation of bitrate for each layer.
>     Changing to first read bitrates and resolution ratios from the flags, if specified.
>     If not specified, reverting to the old code are setting the values automatically.
> - Changing the parameters in LayerFilteringTransport, replacing
>     xx_discard_thresholds with selected_xx, to make it easier to use for the end user.
>
> Committed: https://crrev.com/87f83a9a27d657731ccb54025bc04ccad0da136e
> Cr-Commit-Position: refs/heads/master@{#10215}

TBR=pbos@webrtc.org,mflodman@webrtc.org,ivica@webrtc.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/7a975f75e7fa7a9335411ef22b6687f78f7b297f
Cr-Commit-Position: refs/heads/master@{#10252}

[sprang_webrtc, 2015-10-12 13:33:04]

Created Revert of Adding support for simulcast and spatial layers into
VideoQualityTest

[commit-bot: I haz the power, 2015-10-12 13:33:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1397363002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1397363002/1

[commit-bot: I haz the power, 2015-10-12 13:33:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-12 13:33:35]

Patchset 1 (id:??) landed as
https://crrev.com/7a975f75e7fa7a9335411ef22b6687f78f7b297f
Cr-Commit-Position: refs/heads/master@{#10252}