GitLab

Changes WebUI setup to a MojoWebUI for chrome://bluetooth-internals page.
Adds mojom files for Bluetooth service definition and internals page handler.
Adds basic Bluetooth device retrieval using starter Bluetooth service
implementation for logging on web front end.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
BUG=651282

Review-Url: https://codereview.chromium.org/2357383002
Cr-Commit-Position: refs/heads/master@{#422570}