Bug 994993 - IonMonkey: Don't disable math function optimization when there's no cache. r=jandem
Bug 994548 - Fix masks being affected by partial updates in BasicCompositor. r=mattwoodrow
Bug 993475 - Support masks on color layers in BasicCompositor. r=mattwoodrow
Bug 993475 - Consolidate masking code in BasicCompositor and BasicLayersImpl. r=mattwoodrow