Revert of Add explicit support for discovering the GpuProcess to Telemetry's 'Model'.

Revert of Add explicit support for discovering the GpuProcess to Telemetry's 'Model'. (patchset #1 id:1 of https://codereview.chromium.org/816833006/)

Reason for revert:
Since this CL landed, we've been seeing flakes in Mac 10.9 telemetry_unittests. It's not clear that this CL is responsible, but the timing is suspicious.

Recent 10.9 failures:
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20(dbg)

Detailed log: https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%29/builds/1965/steps/telemetry_unittests/logs/stdio

Original issue's description:
> Add explicit support for discovering the GpuProcess to Telemetry's 'Model'.
>
> BUG=
>
> Committed: https://crrev.com/f6ade006723de6a100b6dd6b545cb5916b197925
> Cr-Commit-Position: refs/heads/master@{#311486}

TBR=skyostil@chromium.org,tonyg@chromium.org,andrewhayden@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Committed: https://crrev.com/8bb2a47135a731b12116feb832a9dc6433729fa2
Cr-Commit-Position: refs/heads/master@{#311592}

[Ryan Hamilton, 2015-01-15 00:44:05]

Created Revert of Add explicit support for discovering the GpuProcess to
Telemetry's 'Model'.

[commit-bot: I haz the power, 2015-01-15 00:44:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/819643006/1

[commit-bot: I haz the power, 2015-01-15 00:45:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-15 00:48:26]

Patchset 1 (id:??) landed as
https://crrev.com/8bb2a47135a731b12116feb832a9dc6433729fa2
Cr-Commit-Position: refs/heads/master@{#311592}

[Andrew Hayden (chromium.org), 2015-01-15 08:54:46]

On 2015/01/15 00:48:26, I haz the power (commit-bot) wrote:
> Patchset 1 (id:??) landed as
> https://crrev.com/8bb2a47135a731b12116feb832a9dc6433729fa2
> Cr-Commit-Position: refs/heads/master@{#311592}

This revert doesn't seem to have fixed anything:
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...

Since the original change did nothing but add some additional fields to the
model, I don't see how it could possibly have an effect on the number of browser
processes running (which is what the error logs say). I'll talk to one of the
OWNERS today but am inclined to revert the revert, based on the continued
flakiness of the tests.

[Sami, 2015-01-15 10:37:43]

On 2015/01/15 08:54:46, Andrew Hayden wrote:
> On 2015/01/15 00:48:26, I haz the power (commit-bot) wrote:
> > Patchset 1 (id:??) landed as
> > https://crrev.com/8bb2a47135a731b12116feb832a9dc6433729fa2
> > Cr-Commit-Position: refs/heads/master@{#311592}
> 
> This revert doesn't seem to have fixed anything:
>
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...
>
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...
>
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...
>
https://build.chromium.org/p/chromium.mac/builders/Mac10.9%20Tests%20%28dbg%2...
> 
> Since the original change did nothing but add some additional fields to the
> model, I don't see how it could possibly have an effect on the number of
browser
> processes running (which is what the error logs say). I'll talk to one of the
> OWNERS today but am inclined to revert the revert, based on the continued
> flakiness of the tests.

Agreed, as far as I can see this change isn't related to the flake. Let's reland
it.

[Andrew Hayden (chromium.org), 2015-01-15 10:56:58]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/847433005/ by andrewhayden@chromium.org.

The reason for reverting is: Per discussion with owner (skyostil@) and analysis
of subsequent flakes that continued to demonstrate the reported problem after
the revert, we've concluded that the original change is not responsible for the
flakes. Reverting the revert..