[NTP::Push] Add Content Suggestions GCM App Handler

components/ntp_snippets/pref_names.h

Index: components/ntp_snippets/pref_names.h
diff --git a/components/ntp_snippets/pref_names.h b/components/ntp_snippets/pref_names.h
index c640965e9ee1aedf499cd58d65fa999ea16ed2a7..f7885ab4a49880446f068a13a9fbd7f9858c05a2 100644
--- a/components/ntp_snippets/pref_names.h
+++ b/components/ntp_snippets/pref_names.h
@@ -94,6 +94,11 @@ extern const char kClickBasedCategoryRankerLastDecayTime[];
 // news push updates,
 extern const char kContentSuggestionsSubscriptionDataToken[];
 
+// The pref name for the subscription token received from the gcm server. As

[jkrcal, 2017/06/09 09:10:10]

The comment does not clarify the difference to
kContentSuggestionsSubscriptionDataToken to me. Can you please expand the
comments a bit?

[mamir, 2017/06/09 13:52:58]

PTAL.

+// recommended by the GCM team, it is cached in pref for faster bookkeeping to
+// see if subscription exists..

[jkrcal, 2017/06/09 09:10:10]

nit: Remove one of the trailing dots.

[mamir, 2017/06/09 13:52:58]

Done.

+extern const char kContentSuggestionsGCMSubscriptionTokenCache[];
+
 }  // namespace prefs
 }  // namespace ntp_snippets