Add more features to ntp-tiles-internal

components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_CLIENT_H_
 #define COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_CLIENT_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "components/ntp_tiles/ntp_tile_source.h"
 
 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 {
  public:
   // 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,
       const base::Callback<void(const base::ListValue*)>& callback) = 0;
 
   // Invokes a function in Javascript. See content::WebUI and web::WebUIIOS.
   virtual void CallJavascriptFunctionVector(
       const std::string& name,
       const std::vector<const base::Value*>& values) = 0;
 
   // Convenience function for CallJavascriptFunctionVector().
   template <typename... Arg>
   void CallJavascriptFunction(const std::string& name, const Arg&... arg) {
     CallJavascriptFunctionVector(name, {&arg...});
   }
 
  protected:
   NTPTilesInternalsMessageHandlerClient();
   virtual ~NTPTilesInternalsMessageHandlerClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NTPTilesInternalsMessageHandlerClient);
 };
 
 }  // namespace ntp_tiles
 
 #endif  // COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_CLIENT_H_