Revert of Add alternate SkPicture::clone

Revert of Add alternate SkPicture::clone (https://codereview.chromium.org/381193002/)

Reason for revert:
Going to try to just remove the many-at-once clone interface

Original issue's description:
> Add alternate SkPicture::clone
> 
> This adds an alternate version of SkPicture::clone for two reasons:
> 
> 1) Chromium uses the SkPicture copy constructor to unpack the pictures from the old-style clone interface (and I would like to remove the copy ctor)
> 
> 2) This is part of the long term plan to wean Chrome off of cloning. Once pictures are thread safe we will switch the new SkPicture::clone call to just return 'this'. From there it is a small step to removing clone entirely.
> 
> Note that the two versions of clone() is temporary. Once this is landed (and rolled) I will land a Chrome-side patch to remove their use of the old interface (Use new SkPicture::clone interface - https://codereview.chromium.org/380323002/)
> 
> Committed: https://skia.googlesource.com/skia/+/e372e78223a8ce916d276d6e0420d552fb0267e9

TBR=mtklein@google.com,reed@google.com
NOTREECHECKS=true
NOTRY=true

Committed: https://skia.googlesource.com/skia/+/ffc75efc1a4c231286c773ff090ec84fc16e9422

[robertphillips, 2014-07-11 13:45:15]

Created Revert of Add alternate SkPicture::clone

[commit-bot: I haz the power, 2014-07-11 13:45:55]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/robertphillips@google.com/386933004/1

[commit-bot: I haz the power, 2014-07-11 13:46:01]

Change committed as ffc75efc1a4c231286c773ff090ec84fc16e9422