ash: Restore user selected rotation on startup
Display preferences saves the user selected rotation. We want to restore
it on startup otherwise the rotation will not be restored after the
first Chrome restart.
Example reproduction steps:
1) Log in
2) Set rotation to 90 degrees
3) Restart chrome (this will be fine since it reads the 90 degree
rotation, though it will write a rotation of 0 degrees)
4) Restart chrome (this will show with a rotation of 0 degrees)
BUG=498895
Review URL: https://codereview.chromium.org/
1177863002
Cr-Commit-Position: refs/heads/master@{#334152}