Revert of [telemetry] Add a V8GCTimes measurement and benchmarks.

Revert of [telemetry] Add a V8GCTimes measurement and benchmarks. (patchset #3 id:40001 of https://codereview.chromium.org/898673005/)

Reason for revert:
Broke the perf bots again due to http://crbug.com/456845

Original issue's description:
> [telemetry] Add a V8GCTimes measurement and benchmarks.
>
> Replaces the v8_stats metric with a v8_gc_times
> measurement.  This new measurement measures the amount of
> time spent in GC during the whole benchmark rather than
> just during gestures.
>
> The following gc metrics are measured:
>   v8_gc_incremental_marking
>   v8_gc_incremental_marking_idle_deadline_overrun
>   v8_gc_incremental_marking_outside_idle
>   v8_gc_incremental_marking_percentage_idle
>   v8_gc_mark_compactor
>   v8_gc_mark_compactor_idle_deadline_overrun
>   v8_gc_mark_compactor_outside_idle
>   v8_gc_mark_compactor_percentage_idle
>   v8_gc_scavenger
>   v8_gc_scavenger_idle_deadline_overrun
>   v8_gc_scavenger_outside_idle
>   v8_gc_scavenger_percentage_idle
>   v8_gc_total
>   v8_gc_total_idle_deadline_overrun
>   v8_gc_total_outside_idle
>
> It also measures the duration of the measurement and the
> amount of CPU time used.
>
> The v8_garbage_collection_cases benchmark is modified to
> use this new v8_gc_times measurement, and v8.top_25_smooth
> and v8.key_mobile_sites_smooth benchmarks have been added.
>
> Since v8_garbage_collection_cases was the only benchmark to
> use the is_fast metric type, and these measurements are now
> done as part of the v8_gc_times measurement now, this CL
> also removes the fast metric type.
>
> Perf Sherrifs: Since this CL changes he way in which the GC
> measurements are done it may cause a movement in the
> v8_garbage_collection_cases benchmarks.
>
> Committed: https://crrev.com/452de5927e54e1da0d57a4b2df8b447f4d442360
> Cr-Commit-Position: refs/heads/master@{#314868}
>
> Committed: https://crrev.com/e65bf3eeb5227de0bb05f08169719d06e518de8b
> Cr-Commit-Position: refs/heads/master@{#315550}

TBR=skyostil@chromium.org,hpayer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/95929c4cb53862160972c9d4a3a9e3625c6d2fe7
Cr-Commit-Position: refs/heads/master@{#315580}

[rmcilroy, 2015-02-10 17:18:46]

Created Revert of [telemetry] Add a V8GCTimes measurement and benchmarks.

[commit-bot: I haz the power, 2015-02-10 17:19:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/908223003/1

[commit-bot: I haz the power, 2015-02-10 17:20:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-10 17:21:24]

Patchset 1 (id:??) landed as
https://crrev.com/95929c4cb53862160972c9d4a3a9e3625c6d2fe7
Cr-Commit-Position: refs/heads/master@{#315580}