Stop showing notifications if they're ignored

chrome/browser/ntp_snippets/ntp_snippets_prefs.cc

Index: chrome/browser/ntp_snippets/ntp_snippets_prefs.cc
diff --git a/chrome/browser/ntp_snippets/ntp_snippets_prefs.cc b/chrome/browser/ntp_snippets/ntp_snippets_prefs.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c63c8a90de92b4e085b256f82930e205c5fe9b37
--- /dev/null
+++ b/chrome/browser/ntp_snippets/ntp_snippets_prefs.cc
@@ -0,0 +1,8 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/ntp_snippets/ntp_snippets_prefs.h"
+
+const char kContentSuggestionsConsecutiveIgnoredPrefName[] =
+    "ntp.content_suggestions.notifications.consecutive_ignored";