Bug 827888: Fix usage of sIsParing variable [r=echou,qdot]

The variable sIsPairing signals to the Bluetooth pairing response
notifier if pairing is still requested.

Being a boolean value, the variable only supported one pairing request
at a time. To support multiple parallel pairing requests, this patch
converts it into a counter. The counter is atomic, because notifier
calls run in separate threads.

Additionally, we now set sIsPairing before starting the pairing request.
Otherwise the notifier might run before we can increment the variable.
Bug 827888: Explicitly call notifier if DBUS call completes early [r=echou,qdot]

If a DBUS call completes before we can set the notifier function, the
call's response never gets handled. To workaround this problem, we now
call the notifier explicitly if the call completes this early.

It can still happen that the call's response gets lost, but this
workaround greatly improves the success rate for our problem of handling
errors during Bluetooth device pairing; from maybe 10% to 75%.
Bug 828838: Fix nsCSSRuleProcessor init-list order. r=heycam
Bug 828863 - followup, forgotten typo r=past
Bug 818575 - Make TransformShadowTree transform all descendant scrollable layers instead of just the first. r=roc

--HG--
extra : rebase_source : 2befc9553af0be20643940e8bf71c0f71d13403e
Bug 818575 - Only sync viewport for primary layer. r=cjones

--HG--
extra : rebase_source : 3221f8a45c9fce9cc51d5f59a19ee50886ff892f