Stop calling jpeg_finish_decompress()

jpeg_finish_decompress() does several things:
(1) Reads to the end of the image stream.
(2) Calls term_src(), a client provided function that
indicates we are done with the memory stream.  Our current
implementation of term_src() does nothing.
(3) Calls jpeg_abort() which aborts the decode and cleans
up some memory.

I don't think we need to call this anymore.

(1) seems irrelevant.

It seems a little dangerous to get rid of (2), but it is
fine while our implementation of term_src() does nothing.

(3) We will call jpeg_destroy() on destruction of the
JpegDecoderManager.  This should free all the memory,
making it unnecessary to call jpeg_abort() beforehand.

BUG=skia:4040

Review URL: https://codereview.chromium.org/1370323004
3 files changed