Revert "SkJpegCodec: Add SkJpegSourceMgr"

This reverts commit 7d0c572a060dd71bc917a5e26ccb9667fc5e4e31.

Reason for revert: Chrome roller failing

Original change's description:
> SkJpegCodec: Add SkJpegSourceMgr
>
> The current skjpeg_source_mgr (in SkJpegUtility.cpp/h) is effectively
> two implementations (buffered vs in-memory) controlled via if
> statements.
>
> Turn these into two implementations of a pure virtual interface
> SkJpegSourceMgr. The reason for this it that there will be a third
> interface added for buffered non-seekable sources (which will
> run an SkJpegSegmentScanner on the data as it is read).
>
> Leave the pre-existing skjpeg_source_mgr in place because it may
> be used in other places. It will be removed separately.
>
> Bug: skia:14031
> Change-Id: Iae87c0da307dfec50c95168c50486c807d335526
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/633461
> Reviewed-by: Brian Osman <brianosman@google.com>
> Commit-Queue: Christopher Cameron <ccameron@google.com>

Bug: skia:14031
Change-Id: I55e020bdcae3ba557f2e90fab9d150ec47f22921
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/635576
Auto-Submit: Brian Osman <brianosman@google.com>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
6 files changed