Add kill switch for Notification images

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index ca9cac8b9bcc5afe2c8808cd87bd5279f7613b45..b217d9f87396b11a38ba3a0f6755c43c2de0039d 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -111,6 +111,10 @@ const base::Feature kMemoryCoordinator {
 const base::Feature kNonValidatingReloadOnNormalReload{
     "NonValidatingReloadOnNormalReload", base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Kill switch for Web Notification content images.
+const base::Feature kNotificationContentImage{"NotificationContentImage",
+                                              base::FEATURE_ENABLED_BY_DEFAULT};
+
 // An experiment to optimize resource loading IPC for small resources.
 // http://crbug.com/580928
 const base::Feature kOptimizeLoadingIPCForSmallResources{