Revert of First pass BackgroundTracingManager.

Revert of First pass BackgroundTracingManager. (patchset #15 id:450001 of https://codereview.chromium.org/1089253003/)

Reason for revert:
Failed TSan Tests.

http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20TSan%20Tests/builds/4795

Original issue's description:
> Skeleton for BackgroundTracingManager.
>
> This version mostly just directs the TracingController using the specified BackgroundTracingConfig and pushes the compressed trace out to the BackgroundTracingUploadSink.
>
> Specifically, we implement the PREEMPTIVE_TRACING_MODE for the rule MONITOR_AND_DUMP_WHEN_TRIGGER_NAMED, which should allow us to get an experiment going on desktop with a simple trigger and upload.
>
> We can then follow up with additional CL's implementing the rest of the functionality from the clientside doc below.
>
> Needs to land first: https://codereview.chromium.org/1088673003/
>
> Slow Reports Clientside: https://docs.google.com/document/d/1qZmXmodxOKmsTRO27z2WlH2h9Kpf-kjV-k-1pJIogIE/edit?pli=1
>
> go/slow-reports
>
> Committed: https://crrev.com/c9cd43c8963301a6b1ebfb74c4eb03b8c733e9f9
> Cr-Commit-Position: refs/heads/master@{#330942}

TBR=dsinclair@chromium.org,nduca@chromium.org,oysteine@chromium.org,sievers@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/aefbdd17287f7591cca603938629f2d55cbe9fda
Cr-Commit-Position: refs/heads/master@{#330949}

[shatch, 2015-05-21 17:53:01]

Created Revert of First pass BackgroundTracingManager.

[commit-bot: I haz the power, 2015-05-21 17:54:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1147383002/1

[commit-bot: I haz the power, 2015-05-21 17:55:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-21 17:56:33]

Patchset 1 (id:??) landed as
https://crrev.com/aefbdd17287f7591cca603938629f2d55cbe9fda
Cr-Commit-Position: refs/heads/master@{#330949}