diff --git a/mozilla/gfx/src/mac/nsRenderingContextMac.cpp b/mozilla/gfx/src/mac/nsRenderingContextMac.cpp
index cc465e6ca79..5048f57aff0 100644
--- a/mozilla/gfx/src/mac/nsRenderingContextMac.cpp
+++ b/mozilla/gfx/src/mac/nsRenderingContextMac.cpp
@@ -1394,3 +1394,13 @@ NS_IMETHODIMP nsRenderingContextMac::RetrieveCurrentNativeGraphicData(PRUint32 *
 {
   return NS_OK;
 }
+
+NS_IMETHODIMP nsRenderingContextMac::InvertRect(const nsRect& aRect)
+{
+  return NS_OK;
+}
+
+NS_IMETHODIMP nsRenderingContextMac::InvertRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight)
+{
+  return NS_OK;
+}
diff --git a/mozilla/gfx/src/mac/nsRenderingContextMac.h b/mozilla/gfx/src/mac/nsRenderingContextMac.h
index c418917a6f4..e80189a4d49 100644
--- a/mozilla/gfx/src/mac/nsRenderingContextMac.h
+++ b/mozilla/gfx/src/mac/nsRenderingContextMac.h
@@ -120,6 +120,9 @@ public:
                                const nsRect &aDestBounds, PRUint32 aCopyFlags);
   NS_IMETHOD RetrieveCurrentNativeGraphicData(PRUint32 * ngd);
 
+  NS_IMETHOD InvertRect(const nsRect& aRect);
+  NS_IMETHOD InvertRect(nscoord aX, nscoord aY, nscoord aWidth, nscoord aHeight);
+
   //locals
   NS_IMETHOD SetPortTextState();
   nsresult   Init(nsIDeviceContext* aContext, GrafPtr aPort);