Revert of Replace EncodeBitmap with an interface. (patchset #11 id:190001 of https...

Revert of Replace EncodeBitmap with an interface. (patchset #11 id:190001 of https://codereview.chromium.org/784643002/)

Reason for revert:
Compilation is failing on some bots

Original issue's description:
> Replace EncodeBitmap with an interface.
>
> Gives more flexibility to the caller to decide whether to use the
> encoded data returned by refEncodedData().
>
> Provides an implementation that supports the old version of
> SkPicture::serialize().
>
> TODO: Update Chrome, so we can remove SK_LEGACY_ENCODE_BITMAP entirely
>
> BUG=skia:3190
>
> Committed: https://skia.googlesource.com/skia/+/0c4aba6edb9900c597359dfa49d3ce4a41bc5dd1

TBR=reed@google.com,scroggo@google.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:3190

Review URL: https://codereview.chromium.org/787833002