Bug 1072313: P2 Prevent instanciating MacIOSurfaceLib directly. r=mattwoodrow

This class only contains static members.

gfx/2d/MacIOSurface.h

@@ -62,7 +62,7 @@ enum CGContextType {
 
 CGContextType GetContextType(CGContextRef ref);
 
-class MacIOSurface : public mozilla::external::AtomicRefCounted<MacIOSurface> {
+class MacIOSurface final : public mozilla::external::AtomicRefCounted<MacIOSurface> {
 public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(MacIOSurface)
   typedef mozilla::gfx::SourceSurface SourceSurface;
@@ -82,7 +82,7 @@ public:
   explicit MacIOSurface(const void *aIOSurfacePtr,
                         double aContentsScaleFactor = 1.0,
                         bool aHasAlpha = true);
-  virtual ~MacIOSurface();
+  ~MacIOSurface();
   IOSurfaceID GetIOSurfaceID();
   void *GetBaseAddress();
   void *GetBaseAddressOfPlane(size_t planeIndex);
@@ -125,9 +125,9 @@ private:
   bool mHasAlpha;
 };
 
-class MacIOSurfaceLib: public MacIOSurface {
+class MacIOSurfaceLib {
 public:
-  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(MacIOSurfaceLib)
+  MacIOSurfaceLib() = delete;
   static void                        *sIOSurfaceFramework;
   static void                        *sOpenGLFramework;
   static void                        *sCoreGraphicsFramework;