--- content/canvas/src/nsCanvasRenderingContext2D.cpp.old	2011-08-11 23:40:52.000000000 +0200
+++ content/canvas/src/nsCanvasRenderingContext2D.cpp	2011-08-15 15:49:11.000000000 +0200
@@ -75,6 +75,8 @@
 
 #include "nsReadableUtils.h"
 
+#include "nsIObserverService.h"
+
 #include "nsColor.h"
 #include "nsGfxCIID.h"
 #include "nsIScriptSecurityManager.h"
@@ -3295,6 +3297,10 @@
                 return NS_ERROR_NOT_AVAILABLE;
         }
 
+        nsCOMPtr<nsIObserverService> os(do_GetService("@mozilla.org/observer-service;1"));
+        os->NotifyObservers(imgElt, "canvas-draw-image", nsnull);
+
+
         imgsurf = res.mSurface.forget();
         imgSize = res.mSize;
 
