Reland of Pass --images '' to nanobench to disable image benchmarking.

Reland of Pass --images '' to nanobench to disable image benchmarking. (patchset #1 id:1 of https://codereview.chromium.org/1400633002/ )

Reason for revert:
Still breaking. e.g.

http://build.chromium.org/p/client.skia/builders/Test-iOS-Clang-iPad4-GPU-SGX554-Arm7-Debug/builds/1466/steps/nanobench/logs/stdio

http://build.chromium.org/p/client.skia.android/builders/Perf-Android-GCC-Nexus7-GPU-Tegra3-Arm7-Release/builds/2280/steps/nanobench/logs/stdio

Original issue's description:
> Revert of Pass --images '' to nanobench to disable image benchmarking. (patchset #1 id:1 of https://codereview.chromium.org/1381703003/ )
> 
> Reason for revert:
> I have attempted to fix the problems that caused running nanobench with images to fail, so testing to see if they are in fact fixed.
> 
> Original issue's description:
> > Pass --images '' to nanobench to disable image benchmarking.
> > 
> > Enabling image benchmarking has caused most nanobench runs to fail,
> > both Debug and Release.
> > 
> > BUG=skia:3418
> > NOTREECHECKS=true
> > TBR=scroggo@google.com
> > 
> > Committed: https://skia.googlesource.com/skia/+/1f7039c6c5f0f118b629994b0bac255345e5abd6
> 
> BUG=skia:3418
> 
> Committed: https://skia.googlesource.com/skia/+/c2e59caa0a466040f4b4f08cb5604c86b2615efa

TBR=mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:3418
Committed: https://skia.googlesource.com/skia/+/0a3cac8a90e4aed24555815a43fafd53aed009ee

[scroggo, 2015-10-08 21:44:35]

Created Reland of Pass --images '' to nanobench to disable image benchmarking.

[commit-bot: I haz the power, 2015-10-08 21:44:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1396843003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1396843003/1

[commit-bot: I haz the power, 2015-10-08 21:44:55]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/0a3cac8a90e4aed24555815a43fafd53aed009ee