fix bustage and remove dependence on internal header

camino/src/download/nsDownloadListener.h

@@ -51,7 +51,7 @@
 #include "nsIURI.h"
 #include "nsILocalFile.h"
 
-#include "nsExternalHelperAppService.h"
+#include "nsIExternalHelperAppService.h"
 
 
 // maybe this should replace nsHeaderSniffer too?

camino/src/download/nsDownloadListener.mm

@@ -40,6 +40,7 @@
 #import "NSString+Utils.h"
 
 #include "nsDownloadListener.h"
+#include "nsIObserver.h"
 
 #include "nsIWebProgress.h"
 #include "nsIRequest.h"