Bug 1004191 - Destroy LayerTransactionChild. r=nical, r=bjacob, a=1.4+
Bug 1003006 - Move b2g camera rotation checks to MainThread. r=mikeh, a=1.4+
Bug 1014209 - Only call DrawBuffers if necessary. r=jgilbert, a=1.4+

DrawBuffers seems to cause a flush on the adreno 300 so we only want to do it if we need to.