Convert sensor layout tests to use the new mojo JS bindings.

This change also exposes the SensorProvider interface from the frame.
The frame then forwards the request to the device service. This is
likely what we want in the long term to enforce permission check. And it
also enables layout tests to intercept the interface.

BUG=699569

Change-Id: Ic00466126aac982e57242829a103b0c10ba0f1ba
Reviewed-on: https://chromium-review.googlesource.com/569641
Commit-Queue: Yuzhu Shen <yzshen@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486890}
14 files changed