Add a preference for disabling vibration in notifications.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index d09888ba44a5a689641ff35a30418da3082ce160..0726f0b9f5b86d4a4ba24162bd5086e3e60bf561 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -1182,6 +1182,11 @@ const char kFullscreenAllowed[] = "fullscreen.allowed";
 const char kLocalDiscoveryNotificationsEnabled[] =
     "local_discovery.notifications_enabled";
 
+#if defined(OS_ANDROID)
+// Enable vibration for web notifications.
+const char kNotificationsVibrateEnabled[] = "notifications.vibrate_enabled";
+#endif
+
 // Maps from app ids to origin + Service Worker registration ID.
 const char kPushMessagingAppIdentifierMap[] =
     "gcm.push_messaging_application_id_map";