power: Don't emit PowerStateChanged and SuspendStateChanged.

These D-Bus signals are being removed in favor of
simpler SuspendImminent and SuspendDone signals.

BUG=chromium:359619
TEST=updated tests

Change-Id: Ie49e8377593fbd672e81ff846c889a08d734ce8d
Reviewed-on: https://chromium-review.googlesource.com/196274
Commit-Queue: Daniel Erat <[email protected]>
Tested-by: Daniel Erat <[email protected]>
Reviewed-by: Sameer Nanda <[email protected]>
4 files changed