Move OnURLsDeleted from NTPSnippetsService to ContentSuggestionsService

components/ntp_snippets/content_suggestions_provider.h

Index: components/ntp_snippets/content_suggestions_provider.h
diff --git a/components/ntp_snippets/content_suggestions_provider.h b/components/ntp_snippets/content_suggestions_provider.h
index 8d292523a75b6d6c07a27b9f549105d9798ca172..ef160b9dee0a0954ba1b8bfe6bf557660a2a54fe 100644
--- a/components/ntp_snippets/content_suggestions_provider.h
+++ b/components/ntp_snippets/content_suggestions_provider.h
@@ -102,6 +102,14 @@ class ContentSuggestionsProvider {
   virtual void FetchSuggestionImage(const std::string& suggestion_id,
                                     const ImageFetchedCallback& callback) = 0;
 
+  // Removes given list of URLs and associated data (depends on a provider).

[Marc Treib, 2016/08/30 09:42:32]

Removes from where?
s/a provider/the provider/

[vitaliii, 2016/09/02 12:38:30]

Done.

+  // Providers should immediately clear any history-related data associated with
+  // |deleted_rows| or all data if |all_history| is true. If |expired| is true,
+  // then the deletion is due to expiration and providers may ignore it.

[Marc Treib, 2016/08/30 09:42:32]

Would any provider ever care about expired URLs? If not, let's just remove the
parameter, and have the service not forward those events.

[vitaliii, 2016/09/02 12:38:30]

Done.

+  virtual void RemoveURLsFromHistory(bool all_history,
+                                     bool expired,
+                                     const history::URLRows& deleted_rows) = 0;

[vitaliii, 2016/08/30 08:57:31]

Marc, would you mind checking the interface?
I ignore |std::set<GURL>& favicon_urls|, because
1) we do not need them;
2) set of URLs does not look useful.

[Marc Treib, 2016/08/30 09:42:32]

Yup, this sounds reasonable.

[Marc Treib, 2016/08/30 09:42:32]

It might be nice not to use history:: types here, otherwise every provider has
to include some history header. Do we need anything other than the actual URLs?

[vitaliii, 2016/09/02 12:38:30]

Done.

+
   // Removes history from a given time range. The data removed depends on a
   // provider. Note that the data outside the time range may be deleted, for
   // example suggestions, which are based on the time range. Providers should