Revert of vea_unittest: Calculate per-frame encode latency

Revert of vea_unittest: Calculate per-frame encode latency (patchset #16 id:300001 of https://codereview.chromium.org/1117853002/)

Reason for revert:
https://uberchromegw.corp.google.com/i/chromiumos.chromium/builders/X86%20%28chromium%29/builds/4667

chromium-os builders went red. Looks like there's a signed/unsigned comparison.

Original issue's description:
> vea_unittest: Calculate per-frame encode latency
>
> Calculates per-frame encode latency, which is basically the time delay from
> input of each VideoFrame (VEA::Encode()) to output of the corresponding
> BitstreamBuffer (VEA::Client::BitstreamBufferReady()).
>
> It calculates encode latency values at the 50th(median), 75th, and 95th percentiles.
>
> Also fix a wrong comment.
>
> BUG=345181
> TEST=Check "Encode latency for the 50%/75%/95%" in output logs.
>
> Committed: https://crrev.com/b21ffeee2aff4da8edb9808b2227165c37e5ce86
> Cr-Commit-Position: refs/heads/master@{#329819}
>
> Committed: https://crrev.com/738487a69f150975376c36e214c64a77b1ff0cc6
> Cr-Commit-Position: refs/heads/master@{#329838}

TBR=owenlin@chromium.org,posciak@chromium.org,wuchengli@chromium.org,jchuang@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=345181
Committed: https://crrev.com/d671c4abd5ff7c86f25d61c63d75f966bf736b51
Cr-Commit-Position: refs/heads/master@{#329994}

[achuithb, 2015-05-15 00:24:27]

Created Revert of vea_unittest: Calculate per-frame encode latency

[commit-bot: I haz the power, 2015-05-15 00:25:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1145543002/1

[commit-bot: I haz the power, 2015-05-15 00:26:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-15 00:27:57]

Patchset 1 (id:??) landed as
https://crrev.com/d671c4abd5ff7c86f25d61c63d75f966bf736b51
Cr-Commit-Position: refs/heads/master@{#329994}