GitLab

On Linux, older versions of UPower did not have the GetDisplayDevice
method. Trying to call it generates log spam.

Modernize the modified file with base::MakeUnique while we are here.

BUG=695383

Review-Url: https://codereview.chromium.org/2795713003
Cr-Commit-Position: refs/heads/master@{#463358}