Revert of Revert of Standardize "gpu_times" metric names and add GPU rasterization versions.

Revert of Revert of Standardize "gpu_times" metric names and add GPU rasterization versions. (patchset #1 id:1 of https://codereview.chromium.org/896593002/)

Reason for revert:
Reverting the revert; looks like this wasn't the culprit.

Original issue's description:
> Revert of Standardize "gpu_times" metric names and add GPU rasterization versions. (patchset #2 id:20001 of https://codereview.chromium.org/875473003/)
>
> Reason for revert:
> Speculative revert for crbug.com/453131
>
> Original issue's description:
> > Standardize "gpu_times" metric names and add GPU rasterization versions.
> >
> > The GPU Times metric event names have been standardized to match the
> > names for other metrics. GPU Rasterization versions have also been
> > added for both GPU times tests. Here is the list of test names:
> >   gpu_times.gpu_rasterization.key_mobile_sites_smooth
> >   gpu_times.gpu_rasterization.top_25_smooth
> >   gpu_times.key_mobile_sites_smooth
> >   gpu_times.top_25_smooth
> >
> > R=vmiura@chromium.org
> > BUG=none
> > test=trybots
> >
> > Committed: https://crrev.com/9fbe73b4158beb6beb278af819e075cc3d744210
> > Cr-Commit-Position: refs/heads/master@{#313825}
>
> TBR=vmiura@chromium.org,epenner@chromium.org,dyen@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=none
>
> Committed: https://crrev.com/92a5662c9732fb41f2afc2026ed0e6b4e9c1fcd3
> Cr-Commit-Position: refs/heads/master@{#314192}

TBR=vmiura@chromium.org,epenner@chromium.org,dyen@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=none

Committed: https://crrev.com/d8ea3d2d37fa3469325d960e1f23d3912ed31303
Cr-Commit-Position: refs/heads/master@{#314224}

[oystein (OOO til 10th of July), 2015-02-03 00:29:48]

Created Revert of Revert of Standardize "gpu_times" metric names and add GPU
rasterization versions.

[commit-bot: I haz the power, 2015-02-03 00:31:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/898593004/1

[commit-bot: I haz the power, 2015-02-03 00:33:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-03 00:35:40]

Patchset 1 (id:??) landed as
https://crrev.com/d8ea3d2d37fa3469325d960e1f23d3912ed31303
Cr-Commit-Position: refs/heads/master@{#314224}