[DevTools] Support device orientation override on device with sensors.

Previously, override value was quickly replaced by real data from sensors.
Now, we put sensor data on hold until override is disabled.

This patch also fixes the cleanup/navigation issues with override enabled.

BUG=none

Review URL: https://codereview.chromium.org/209333008

git-svn-id: svn://svn.chromium.org/blink/trunk@170163 bbb929c8-8fbe-4397-9dbb-9b2b20218538