Cleanup linked_ptr -> unique_ptr from profile_manager.h/cc

linked_ptr is deprecated, see bug.

BUG=556939

Change-Id: I2d4812a93ab40009eb4971e4863da529862e898d
Reviewed-on: https://chromium-review.googlesource.com/578582
Commit-Queue: Xiaofeng Zhang <xiaofeng.zhang@intel.com>
Reviewed-by: Bernhard Bauer <bauerb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488878}
2 files changed