Adding tests.

Disabled Jasmine test due to flakiness on dev machine.
Added test for endTime in update().
Enabled updatePlayTime() tests. Will see on Jenkins.
Adding test for updatePlayTime() method.
Adding ProgressSlider notifyThroughHandleEnd() Jasmine tests.
Fixing Jasmine coverage problems.
Removed cover logs.
Fixing flaky test.
Removed code coverage logs.