Remove OwnPtr::release() calls in platform/ (part inspector).

OwnPtr::release() calls can be (1) replaced with std::move(), or
(2) removed entirely (in certain "return" statements).

BUG=611660

Review-Url: https://codereview.chromium.org/1979963002
Cr-Original-Commit-Position: refs/heads/master@{#394341}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: e140a0d3266c78fb085395cf63eb75778fc4413d
8 files changed