Revert of Add the perceptual difference metric to the rebaseline server (https:/...

Revert of Add the perceptual difference metric to the rebaseline server (https://codereview.chromium.org/147453003/)

Reason for revert:
Caused failure in RunGmSelfTests:
http://108.170.219.160:10117/builders/Housekeeper-PerCommit/builds/154/steps/RunGmSelfTests/logs/stdio

Filed:
https://code.google.com/p/skia/issues/detail?id=2160

Original issue's description:
> Add the perceptual difference metric to the rebaseline server
>
> * Finds the location of the skpdiff binary.
> * Calculates the perceptual difference percentage using the skpdiff binary.
> * Replaces the weightedDiffMeasure in view.html with perceptualDifferent.
>
> BUG=skia:2019
> NOTRY=true
>
> Committed: http://code.google.com/p/skia/source/detail?r=13398

R=epoger@google.com
TBR=epoger@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:2019

Author: rmistry@google.com

Review URL: https://codereview.chromium.org/131453017

git-svn-id: http://skia.googlecode.com/svn/trunk@13399 2bbb7eff-a529-9590-31e7-b0007b416f81