Introduce a request throttler for limiting requests in mobile NTP.

components/ntp_snippets/pref_names.cc

Index: components/ntp_snippets/pref_names.cc
diff --git a/components/ntp_snippets/pref_names.cc b/components/ntp_snippets/pref_names.cc
index ecfb9ee0e6ab4fefb4b559310acb5e4c71c9f1d0..3cc8a1d6c72df8b40029e89558e6436a0e514056 100644
--- a/components/ntp_snippets/pref_names.cc
+++ b/components/ntp_snippets/pref_names.cc
@@ -9,5 +9,8 @@ namespace prefs {
 
 const char kSnippetHosts[] = "ntp_snippets.hosts";
 
+const char kSnippetQuotaDayFormat[] = "ntp_snippets.quota.%s.day";
+const char kSnippetQuotaCountFormat[] = "ntp_snippets.quota.%s.count";

[Marc Treib, 2016/07/19 09:06:17]

Hmmm, this is very uncommon AFAIK. Do you have any precedent for generated pref
names?
If not, then I'd prefer a scheme where the client (i.e. NTPSnippetsFetcher)
registers the prefs itself, and passes the names to the RequestCounter.

[jkrcal, 2016/07/20 09:40:39]

Now, I register all of them in RequestCounter.

+
 }  // namespace prefs
 }  // namespace ntp_snippets