Adding a newline to the warning printf. r=jag.

view/src/nsViewManager.cpp

@@ -872,7 +872,7 @@ void nsViewManager::Refresh(nsIView *aView, nsIRenderingContext *aContext, nsIRe
       localcx->CopyOffScreenBits(ds, wrect.x, wrect.y, wrect, NS_COPYBITS_USE_SOURCE_CLIP_REGION);
   } else {
 #ifdef DEBUG
-    printf("XXX Damage rectangle (%d,%d,%d,%d) does not intersect the widget's view (%d,%d,%d,%d)!",
+    printf("XXX Damage rectangle (%d,%d,%d,%d) does not intersect the widget's view (%d,%d,%d,%d)!\n",
            damageRect.x, damageRect.y, damageRect.width, damageRect.height,
            viewRect.x, viewRect.y, viewRect.width, viewRect.height);
 #endif