Fix BluetoothAdapterProfileChromeOS lifecycle management

Have BluetoothAdapterProfileChromeOS objects managed through
BluetoothAdapterChromeOS, avoiding problems where references were being
left behind in BluetoothSocketChromeOS after deletion.

Adds some unit tests to confirm lifecycle works correctly even when
multiple profiles are requested simultaneously.

This is a resubmit of https://codereview.chromium.org/935383003/ after a revert
for LSan test failures https://codereview.chromium.org/975323002/, a patch with
just changes from the old CL can be found there.

BUG=457978
R=armansito, isherman@chromium.org, keybuk

Review URL: https://codereview.chromium.org/982593002

Cr-Commit-Position: refs/heads/master@{#319721}
11 files changed