Add a flag for enabling/disabling the navigator content utils

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 93f95c050b8dd2be9eb3dc40aee2470732d472d9..0d593e57f3ad0282ad6c0b2c3546483f4d383a00 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -151,6 +151,10 @@ const char kDisableDelegatedRenderer[]      = "disable-delegated-renderer";
 // Disables desktop notifications (default enabled on windows).
 const char kDisableDesktopNotifications[]   = "disable-desktop-notifications";
 
+// Disables experimental navigator content utils implementation.
+const char kDisableNavigatorContentUtils[]  =
+      "disable-navigator-content-utils";
+
 // Disable device motion events.
 const char kDisableDeviceMotion[]           = "disable-device-motion";