[chrome:omnibox] Encapsulate custom elements and update orchestration of inputs

- OmniboxInputs to displatch events with details containing display and query inputs when they change

- OutputController to handle those events, cache display and query inputs, and invoke OmniboxOutputs.refresh

- OmniboxOutputs.refresh to manage updating the HTML from inputs

Bug: 891303
Change-Id: Ice63b04f4eafea5d98e8dddd1f16b17618f2652e
Reviewed-on: https://chromium-review.googlesource.com/c/1299534
Commit-Queue: manuk hovanesian <manukh@chromium.org>
Reviewed-by: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603932}
3 files changed