Fix orange. b=109974, 111088

gfx/src/gtk/nsDeviceContextGTK.cpp

@@ -118,8 +118,6 @@ class nsSystemFontsGTK {
 nscoord nsDeviceContextGTK::mDpi = 96;
 static nsSystemFontsGTK *gSystemFonts = nsnull;
 
-NS_IMPL_ISUPPORTS1(nsDeviceContextGTK, nsIDeviceContext)
-
 nsDeviceContextGTK::nsDeviceContextGTK()
 {
   NS_INIT_REFCNT();

gfx/src/gtk/nsDeviceContextGTK.h

@@ -55,8 +55,6 @@ public:
   nsDeviceContextGTK();
   virtual ~nsDeviceContextGTK();
 
-  NS_DECL_ISUPPORTS
-
   static void Shutdown(); // to be called from module destructor
 
   NS_IMETHOD  Init(nsNativeWidget aNativeWidget);