Add baked-in favicons for default popular sites on NTP

components/ntp_tiles/icon_cacher_impl.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_ICON_CACHER_IMPL_H_
 #define COMPONENTS_NTP_TILES_ICON_CACHER_IMPL_H_
 
+#include <map>
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "base/task/cancelable_task_tracker.h"
 #include "components/ntp_tiles/icon_cacher.h"
 #include "components/ntp_tiles/popular_sites.h"
 
 namespace favicon {
@@ skipping 15 matching lines @@
 namespace ntp_tiles {
 
 class IconCacherImpl : public IconCacher {
  public:
   IconCacherImpl(favicon::FaviconService* favicon_service,
                  std::unique_ptr<image_fetcher::ImageFetcher> image_fetcher);
   ~IconCacherImpl() override;
 
   void StartFetch(PopularSites::Site site,
                   const base::Callback<void(bool)>& done) override;
+  void AddDefaultImage(const PopularSites::Site& site,
+                       int image_resource_id) override;
 
  private:
+  struct DefaultIcon;
+
   void OnGetFaviconImageForPageURLFinished(
       PopularSites::Site site,
       const base::Callback<void(bool)>& done,
       const favicon_base::FaviconImageResult& result);
 
   void OnFaviconDownloaded(PopularSites::Site site,
                            const base::Callback<void(bool)>& done,
                            const std::string& id,
                            const gfx::Image& fetched_image);
 
+  bool ProvideDefaultIcon(const PopularSites::Site& site);
+  void SaveIconForSite(const PopularSites::Site& site, const gfx::Image image);
+
   base::CancelableTaskTracker tracker_;
   favicon::FaviconService* const favicon_service_;
   std::unique_ptr<image_fetcher::ImageFetcher> const image_fetcher_;
+  std::map<const std::string, DefaultIcon> default_icons_;

[sfiera, 2017/02/16 11:14:22]

Instead of having a map here, could PopularSites::Site have a "default resource"
field?

[fhorschig, 2017/02/16 17:06:41]

Yes. It has now and the default resource ID is -1.

 
   DISALLOW_COPY_AND_ASSIGN(IconCacherImpl);
 };
 
 }  // namespace ntp_tiles
 
 #endif  // COMPONENTS_NTP_TILES_ICON_CACHER_IMPL_H_