Revert "impl SkSerial picture procs"

This reverts commit c8226728541fdd6434a7f1b97678246202b0edc5.

Reason for revert: broke old skps

Original change's description:
> impl SkSerial picture procs
> 
> The picture serialization code is a bit of a mess, with duplicated functions for streams and buffers.
> Could not see how to fix that and land this at the same time, but I will try to circle back and
> simplify if possible afterwards.
> 
> Bug: skia:
> Change-Id: I9053fdc476c60f483df013d021e248258181c199
> Reviewed-on: https://skia-review.googlesource.com/83943
> Reviewed-by: Florin Malita <fmalita@chromium.org>
> Commit-Queue: Mike Reed <reed@google.com>

TBR=mtklein@google.com,fmalita@chromium.org,reed@google.com

Change-Id: I68ae019a286691b65cc373cb29c941d6620fd34a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/84460
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
9 files changed