Bug 866232 - Allow the GeckoContentController interface to identify which layer is being operated upon. r=
Bug 866232 - Add an APZCTreeManager to encapsulate the multiple APZCs corresponding to a given layer tree. r=
Bug 866232 - Have the APZCTreeManager update its tree of APZC intances on layer updates. r=
Bug 866232 - Some documentation/variable renaming cleanup. r=
Bug 866232 - Extract a GetCurrentAsyncTransform method in APZC. r=