Revert of add peekPixels to SkCanvas and SkSurface (https://codereview.chromium.org/161733002/)

Reason for revert:
compile issues with gm/xfermodes3

Original issue's description:
> add peekPixels to SkCanvas and SkSurface
>
> clone of https://codereview.chromium.org/159723006/
>
> Committed: https://code.google.com/p/skia/source/detail?r=13427

R=jvanverth@google.com
NOTREECHECKS=true
NOTRY=true

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/163823002

git-svn-id: http://skia.googlecode.com/svn/trunk@13428 2bbb7eff-a529-9590-31e7-b0007b416f81
35 files changed