[remote suggestions] Add separte fetch interval for NTP open trigger

components/ntp_snippets/remote/scheduling_remote_suggestions_provider.h

Index: components/ntp_snippets/remote/scheduling_remote_suggestions_provider.h
diff --git a/components/ntp_snippets/remote/scheduling_remote_suggestions_provider.h b/components/ntp_snippets/remote/scheduling_remote_suggestions_provider.h
index 7a42b470380d3f19fd62a980ab963c62045d6e47..1a41aebeaa3d9cf32f90ba64e57c7234057a6df8 100644
--- a/components/ntp_snippets/remote/scheduling_remote_suggestions_provider.h
+++ b/components/ntp_snippets/remote/scheduling_remote_suggestions_provider.h
@@ -114,6 +114,7 @@ class SchedulingRemoteSuggestionsProvider final
       base::TimeDelta interval_persistent_wifi;
       base::TimeDelta interval_persistent_fallback;
       base::TimeDelta interval_soft_on_usage_event;
+      base::TimeDelta interval_ntp_open;

[jkrcal, 2017/02/15 16:35:34]

nit: can it be soft_on_ntp_opened?
 (opened to make it consistent with the event name; soft_ because it is soft as
well)

Another possibility is to make it more abstract:
  soft_on_priority_usage_event
I think it actually better expresses the core of being a separate interval.

WDYT?

[markusheintz_, 2017/02/15 21:19:29]

soft_on_ntp_opened SGTM. 

Name updated.

   };
 
   enum class TriggerType;
@@ -137,7 +138,7 @@ class SchedulingRemoteSuggestionsProvider final
 
   // Checks whether it is time to perform a soft background fetch, according to
   // |schedule|.
-  bool ShouldRefetchInTheBackgroundNow();
+  bool ShouldRefetchInTheBackgroundNow(TriggerType trigger);
 
   // Returns whether background fetching (for the given |trigger|) is disabled.
   bool BackgroundFetchesDisabled(TriggerType trigger) const;