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..a15bf07d4df044b27acf62a0859c99f5e91a3bc6 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"
 
@@ -41,43 +42,63 @@ IconCacherImpl::IconCacherImpl(
 
 IconCacherImpl::~IconCacherImpl() = default;
 
-void IconCacherImpl::StartFetch(PopularSites::Site site,
-                                const base::Callback<void(bool)>& done) {
+void IconCacherImpl::StartFetch(
+    PopularSites::Site site,
+    const base::Callback<void(bool)>& icon_available) {
   favicon::GetFaviconImageForPageURL(
       favicon_service_, site.url, IconType(site),
       base::Bind(&IconCacherImpl::OnGetFaviconImageForPageURLFinished,
-                 base::Unretained(this), std::move(site), done),
+                 base::Unretained(this), std::move(site), icon_available),
       &tracker_);
 }
 
 void IconCacherImpl::OnGetFaviconImageForPageURLFinished(
     PopularSites::Site site,
-    const base::Callback<void(bool)>& done,
+    const base::Callback<void(bool)>& icon_available,
     const favicon_base::FaviconImageResult& result) {
   if (!result.image.IsEmpty()) {
-    done.Run(false);
+    icon_available.Run(false);
     return;
   }
 
+  if (ProvideDefaultIcon(site)) {
+    icon_available.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),
-                 site, done));
+                 site, icon_available));
 }
 
-void IconCacherImpl::OnFaviconDownloaded(PopularSites::Site site,
-                                         const base::Callback<void(bool)>& done,
-                                         const std::string& id,
-                                         const gfx::Image& fetched_image) {
+void IconCacherImpl::OnFaviconDownloaded(
+    PopularSites::Site site,
+    const base::Callback<void(bool)>& icon_available,
+    const std::string& id,
+    const gfx::Image& fetched_image) {
   if (fetched_image.IsEmpty()) {
-    done.Run(false);
+    icon_available.Run(false);
     return;
   }
 
-  gfx::Image image = fetched_image;
+  SaveIconForSite(site, fetched_image);
+  icon_available.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) {
+  if (site.default_resource_id < 0) {
+    return false;
+  }
+  SaveIconForSite(site, ResourceBundle::GetSharedInstance().GetNativeImageNamed(
+                            site.default_resource_id));
+  return true;
 }
 
 }  // namespace ntp_tiles