Ensure PopularSite icon availability in ntp_tiles.

ios/chrome/browser/ntp_tiles/ios_most_visited_sites_factory.cc

 // 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.
 
 #include "ios/chrome/browser/ntp_tiles/ios_most_visited_sites_factory.h"
 
 #include "base/memory/ptr_util.h"
 #include "components/history/core/browser/top_sites.h"
+#include "components/image_fetcher/image_fetcher_impl.h"
+#include "components/keyed_service/core/service_access_type.h"
+#include "components/ntp_tiles/icon_cacher.h"
 #include "components/ntp_tiles/most_visited_sites.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/favicon/favicon_service_factory.h"
 #include "ios/chrome/browser/history/top_sites_factory.h"
 #include "ios/chrome/browser/ntp_tiles/ios_popular_sites_factory.h"
+#include "ios/chrome/browser/suggestions/ios_image_decoder_impl.h"
 #include "ios/chrome/browser/suggestions/suggestions_service_factory.h"
+#include "ios/web/public/web_thread.h"
 
 std::unique_ptr<ntp_tiles::MostVisitedSites>
 IOSMostVisitedSitesFactory::NewForBrowserState(
     ios::ChromeBrowserState* browser_state) {
+  scoped_refptr<base::SequencedTaskRunner> task_runner =
+      web::WebThread::GetBlockingPool()
+          ->GetSequencedTaskRunnerWithShutdownBehavior(
+              base::SequencedWorkerPool::GetSequenceToken(),
+              base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
   return base::MakeUnique<ntp_tiles::MostVisitedSites>(
       browser_state->GetPrefs(),
       ios::TopSitesFactory::GetForBrowserState(browser_state),
       suggestions::SuggestionsServiceFactory::GetForBrowserState(browser_state),
-      IOSPopularSitesFactory::NewForBrowserState(browser_state), nil);
+      IOSPopularSitesFactory::NewForBrowserState(browser_state),
+      base::MakeUnique<ntp_tiles::IconCacher>(
+          ios::FaviconServiceFactory::GetForBrowserState(
+              browser_state, ServiceAccessType::IMPLICIT_ACCESS),
+          base::MakeUnique<image_fetcher::ImageFetcherImpl>(
+              suggestions::CreateIOSImageDecoder(task_runner),
+              browser_state->GetRequestContext())),
+      nil);
 }