JPEGCodec{RobustSlow}::Decode: refactor to use unique_ptr.

This CL removes the class DecompressDestroyer in favour of
a unique_ptr<> with specific Deleter. Less lines of code.

Functionality covered by gfx_unittest, also under asan bot.

Bug: 868400
Change-Id: I7ac2d254d6f5771a81620b14db7e610ff3b7e4b9
Reviewed-on: https://chromium-review.googlesource.com/1245467
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594638}
2 files changed