Add more features to ntp-tiles-internal

components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h

Index: components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h
diff --git a/components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h b/components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h
index 4a917008cbf2be1c1ac18e0923ac5a30bd961fcf..2c8fdede99a7600529a7169504b23db62495e111 100644
--- a/components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h
+++ b/components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h
@@ -18,12 +18,12 @@ class PrefService;
 namespace base {
 class Value;
 class ListValue;
+class SequencedWorkerPool;
 }  // namespace base
 
 namespace ntp_tiles {
 
 class MostVisitedSites;
-class PopularSites;
 
 // Implemented by embedders to hook up NTPTilesInternalsMessageHandler.
 class NTPTilesInternalsMessageHandlerClient {
@@ -31,17 +31,12 @@ class NTPTilesInternalsMessageHandlerClient {
   // Returns the PrefService for the embedder and containing WebUI page.
   virtual PrefService* GetPrefs() = 0;
 
-  // Returns true if the given source is enabled (even if, in practice, none of
-  // the tiles would come from it).
-  virtual bool DoesSourceExist(NTPTileSource source) = 0;
+  virtual base::SequencedWorkerPool* GetBlockingPool() = 0;
 
   // Creates a new MostVisitedSites based on the context pf the WebUI page.
   virtual std::unique_ptr<ntp_tiles::MostVisitedSites>
   MakeMostVisitedSites() = 0;
 
-  // Creates a new PopularSites based on the context pf the WebUI page.
-  virtual std::unique_ptr<ntp_tiles::PopularSites> MakePopularSites() = 0;
-
   // Registers a callback in Javascript. See content::WebUI and web::WebUIIOS.
   virtual void RegisterMessageCallback(
       const std::string& message,