GitLab

In order to better convey property object ownership,
changed WrapViewForPreferredSize() to take and return std::unique_ptr.

Bug: 961657
Change-Id: Ib06871c5bd0dcef357d160b8784f8541b839f59d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1607707Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Yeol Park <peary2@gmail.com>
Cr-Commit-Position: refs/heads/master@{#663061}