Backed out changeset 55fb3669faea (bug 1013769) for bustage.
Bug 1000103 - Fix intermittent OSX crash in TextureImageTextureSourceOGL::GetFormat. r=mattwoodrow, a=sledru
Bug 1024588 - Turn off useragent updates for tests to avoid hitting the network. r=jmaher, a=test-only
Bug 1009157 - Ensure that we can receive BT enable/disabled events in marionette test every times. r=echou, a=test-only

Ensures that we can always receive that "enabled"/"disabled" event by
installing the event handler *before* we ever enable/disable Bluetooth. Or
we might just miss those events and get a timeout error.
Bug 1025959 - Disable checks for webapp updates during tests. r=jmaher, a=test-only
Bug 995690 - Correct mLastTickWritten to only advance when not blocked. r=roc, a=sledru

mLastTickWritten and offset are stream positions, which do not advance when
the stream is blocked.
Bug 995690 - Don't advance audio output stream position 1 tick beyond what has been produced. r=roc, a=sledru

This may result in repeating a sample sometimes due to rounding effects, but
that should only happen once per unblocked sequence of track frames.