Enable more benchmark_smoke_unittest coverage (Reland)

Enable more benchmark_smoke_unittest coverage (Reland)

Previously, benchmark_smoke_unittest has a heuristic to pick
a benchmark for smoke testing if the benchmark uses a test
in measurement directory.
This patch removes that check, and instead provide a black
list of benchmarks module that we exclude the
benchmark_smoke_unittest to avoid high CQ time.

This helped increases benchmark smoke coverage from 14 benchmarks -> 33 benchmarks
(one benchmark per benchmark module).

On my local linux machine, this increases the cycle time of
benchmark_smoke_unittest from 20s -> 1m7s.

To review this, the 1st patch is from issue 1151013002 at patchset 20001 (http://crrev.com/1151013002#ps20001).
2nd patch adds image_decoding to the black list.

BUG=
CQ_EXTRA_TRYBOTS=tryserver.chromium.perf:linux_perf_bisect;tryserver.chromium.perf:mac_perf_bisect;tryserver.chromium.perf:win_perf_bisect;tryserver.chromium.perf:android_nexus5_perf_bisect

Committed: https://crrev.com/cd42fc33c58a58b4067f5c3c578634205c214958
Cr-Commit-Position: refs/heads/master@{#331157}

[nednguyen, 2015-05-22 15:57:14]

nednguyen@google.com changed reviewers:
+ sullivan@chromium.org

[sullivan, 2015-05-22 16:14:53]

lgtm

[nednguyen, 2015-05-22 16:15:47]

The CQ bit was checked by nednguyen@google.com

[commit-bot: I haz the power, 2015-05-22 16:16:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1154913002/20001

[commit-bot: I haz the power, 2015-05-22 19:27:11]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-22 19:28:03]

Patchset 2 (id:??) landed as
https://crrev.com/cd42fc33c58a58b4067f5c3c578634205c214958
Cr-Commit-Position: refs/heads/master@{#331157}