GitLab

Semi-autogenerated ARCMigrate commit.
Notable issues:
 * Since one of the weak_nsobjects is exposed in a header and I change it to a __weak instead, converted two unit tests to ARC alongside this.
 * Fixed some assignments of newly created views to weak properties by introducing an intermediate local variable to retain the view until it's added as subview.

BUG=624363
TEST=None

Review-Url: https://codereview.chromium.org/2624963003
Cr-Commit-Position: refs/heads/master@{#443240}