[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..d4bdb508250754379e1b0ab404db18850dcc97bc 100644
--- a/components/ntp_snippets/pref_names.h
+++ b/components/ntp_snippets/pref_names.h
@@ -94,6 +94,10 @@ extern const char kClickBasedCategoryRankerLastDecayTime[];
 // news push updates,
 extern const char kContentSuggestionsSubscriptionDataToken[];
 
+// The pref name for the subscription token received from the gcm server. As
+// recommended by the GCM team, it is cached in pref instead of being retrieved
+// over network every time the client subscribe to push updates.

[Peter Beverloo, 2017/06/08 07:02:40]

fwiw, calling GetToken() repeatedly should usually not hit the network. the
preference is just a much faster way for your own bookkeeping to see if a
subscription exists.

[mamir, 2017/06/08 10:31:38]

Done.

+extern const char kContentSuggestionsGCMSubscriptionTokenCache[];

[Peter Beverloo, 2017/06/08 07:02:40]

nit: blank line after this.

[mamir, 2017/06/08 10:31:38]

Done.

 }  // namespace prefs
 }  // namespace ntp_snippets