MD Settings: Add display layout

This correctly sizes and positions displays, but does not support
dragging yet.

BUG=547080
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:closure_compilation

For trivial change to display_info_provider_chromeos.cc:
TBR=asargent@chromium.org

Review-Url: https://codereview.chromium.org/2084673003
Cr-Commit-Position: refs/heads/master@{#401989}
10 files changed