Switch SupportsUserData uses to use unique_ptr.

The interface taking a raw pointer is deprecated and being removed.

BUG=690937

Review-Url: https://codereview.chromium.org/2853443002
Cr-Original-Commit-Position: refs/heads/master@{#468008}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 37c9356daeb495268f0ccc950c2c8095c0edd0e9
23 files changed