Reland - [DeviceService] Add service tests for VibrationManager.

Original CL was reverted because it appears to have broken
service_unittests on Nexus 5X.
This CL fixes it and relands.

VibrationManagerImpl.java is in //device/vibration while the
VibrationManagerImplTest.java is still in //content,
to be able to hide all //device/vibration impl inside Device Service,
we must eliminate this concrete dependency on //device/vibration from
content layer.

As VibrationManagerImplTest.java is an integration test based on
content shell test infra, we can't move it outside of //content.
So we consider to use other tests to replace it, while the renderer-side
testing has already been covered by layout tests created at
https://codereview.chromium.org/2731953003/, so we create this CL to
cover the VibrationManager interface impl testing:
 - creates an infra for Device Service service tests.
 - adds a new service test for VibrationManager interface.

Then after this CL we'll be able to hide all vibration impl inside
Device Service with a follow-up CL.

BUG=689379
TEST=service_unittests
TBR=avi@chromium.org

Review-Url: https://codereview.chromium.org/2774783003
Cr-Original-Commit-Position: refs/heads/master@{#463612}
Committed: https://chromium.googlesource.com/chromium/src/+/9c17bee62f1e16224fabb7c83bbeaab719015761
Review-Url: https://codereview.chromium.org/2814013002
Cr-Commit-Position: refs/heads/master@{#463915}
14 files changed