Revert of Added a GLBench for testing performance of vec4 vs scalar...

Revert of Added a GLBench for testing performance of vec4 vs scalar for coverage in generated shaders. (patchset #4 id:40002 of https://codereview.chromium.org/1225383002/)

Reason for revert:
This is breaking a buildbot. See https://chromegw.corp.google.com/i/client.skia/builders/Test-Win8-MSVC-ShuttleB-GPU-HD4600-x86_64-Debug-ANGLE/builds/172/steps/nanobench/logs/stdio

We get the following error: ERROR::SHADER::COMPLIATION_FAILED: ERROR: 0:8: '0.f' : Floating-point suffix unsupported prior to GLSL ES 3.00 
ERROR: 0:8: '0.f' : syntax error 


Original issue's description:
> Added a glBench for testing performance of vec4 vs scalar coverage in generated shaders.
> 
> Added bench for timing vec4 vs scalar type for coverage in shaders
> 
> BUG=skia:
> 
> Committed: https://skia.googlesource.com/skia/+/6104ced165f17eb2f765ace354d5895c0bc890c5

TBR=joshualitt@google.com,tomhudson@google.com,wangyix@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed: https://skia.googlesource.com/skia/+/cd8c499f2e5126a8b5edee09d0debd8d298210fd

[scroggo, 2015-07-13 19:03:15]

Created Revert of Added a GLBench for testing performance of vec4 vs scalar for
coverage in generated shaders.

[tomhudson, 2015-07-13 19:04:25]

On 2015/07/13 19:03:15, scroggo wrote:
> Created Revert of Added a GLBench for testing performance of vec4 vs scalar
for
> coverage in generated shaders.

Thanks, Leon.

LGTM :(