Revert of Fix memory leak in SkGradientShader. (https://codereview.chromium.org/240303003/)

Reason for revert:
This and https://codereview.chromium.org/207683004 are causing memory leaks.

Original issue's description:
> Fix memory leak in SkGradientShader.
>
> Make sure pointer to gradient shader cache is unreffed in SkGradientShaderBase::getGradientTableBitmap.
> Rename methods returning a "pre-reffed" object to indicate obligations.
>
> BUG=skia:1976
>
> Committed: http://code.google.com/p/skia/source/detail?r=14223

R=reed@google.com, scroggo@google.com, dominikg@chromium.org
TBR=dominikg@chromium.org, reed@google.com, scroggo@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:1976

Author: bungeman@google.com

Review URL: https://codereview.chromium.org/241603002

git-svn-id: http://skia.googlecode.com/svn/trunk@14245 2bbb7eff-a529-9590-31e7-b0007b416f81
4 files changed