Add baked-in favicons for default popular sites on NTP

components/ntp_tiles/icon_cacher_impl.cc

Index: components/ntp_tiles/icon_cacher_impl.cc
diff --git a/components/ntp_tiles/icon_cacher_impl.cc b/components/ntp_tiles/icon_cacher_impl.cc
index cb957ea010e58bcd9e70444e6dc578aed426c45e..d2289f4f2a3ec9f6d14b9fa5955b685cf739510b 100644
--- a/components/ntp_tiles/icon_cacher_impl.cc
+++ b/components/ntp_tiles/icon_cacher_impl.cc
@@ -11,6 +11,7 @@
 #include "components/favicon_base/favicon_types.h"
 #include "components/favicon_base/favicon_util.h"
 #include "components/image_fetcher/image_fetcher.h"
+#include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 #include "url/gurl.h"
 
@@ -30,6 +31,14 @@ const GURL& IconURL(const PopularSites::Site& site) {
 
 }  // namespace
 
+struct IconCacherImpl::DefaultIcon {
+  DefaultIcon(const PopularSites::Site& popular_site, int image_resource_id)
+      : site(popular_site), image_resource(image_resource_id) {}
+
+  PopularSites::Site site;
+  int image_resource;
+};
+
 IconCacherImpl::IconCacherImpl(
     favicon::FaviconService* favicon_service,
     std::unique_ptr<image_fetcher::ImageFetcher> image_fetcher)
@@ -59,6 +68,11 @@ void IconCacherImpl::OnGetFaviconImageForPageURLFinished(
     return;
   }
 
+  if (ProvideDefaultIcon(site)) {
+    done.Run(true);
+    // Don't return. We want to fetch to update possibly stale images.
+  }
+
   image_fetcher_->StartOrQueueNetworkRequest(
       std::string(), IconURL(site),
       base::Bind(&IconCacherImpl::OnFaviconDownloaded, base::Unretained(this),
@@ -74,10 +88,31 @@ void IconCacherImpl::OnFaviconDownloaded(PopularSites::Site site,
     return;
   }
 
-  gfx::Image image = fetched_image;
+  SaveIconForSite(site, fetched_image);
+  done.Run(true);
+}
+
+void IconCacherImpl::SaveIconForSite(const PopularSites::Site& site,
+                                     gfx::Image image) {
   favicon_base::SetFaviconColorSpace(&image);
   favicon_service_->SetFavicons(site.url, IconURL(site), IconType(site), image);
-  done.Run(true);
+}
+
+bool IconCacherImpl::ProvideDefaultIcon(const PopularSites::Site& site) {
+  auto it = default_icons_.find(site.url.spec());
+  if (it == default_icons_.end()) {
+    return false;
+  }
+  const DefaultIcon& icon = it->second;
+  SaveIconForSite(icon.site, ResourceBundle::GetSharedInstance().GetImageNamed(
+                                 icon.image_resource));
+  return true;
+}
+
+void IconCacherImpl::AddDefaultImage(const PopularSites::Site& site,
+                                     int image_resource_id) {
+  default_icons_.insert(
+      std::make_pair(site.url.spec(), DefaultIcon(site, image_resource_id)));
 }
 
 }  // namespace ntp_tiles