Use the supplied memory for YUV decoding.

Use the supplied memory for YUV decoding.

As some kind of optimization the yuv decoder replaced some pointers
to point to decoder-internal memory when an API user asked for
yuv data. That often worked, but failed if the data needed to
outlive the decoder. It was also a violation of the API contract.

This replaces that with a buffer copy. It will be slower but will avoid
random bitmap errors that also happened randomly on cq try bots.

This is a stopgap solution while a better solution is designed, coded and
tested.

BUG=455235
R=sugoi@chromium.org,dongseong.hwang@intel.com

Review URL: https://codereview.chromium.org/901573004

Cr-Commit-Position: refs/heads/master@{#314865}