[Chromecast] Bundle fonts into browser

Make chromecast load additional font files from fonts/.

Bug: 69627595
Test: On chromecast, force HTML elements to use local font.
Change-Id: Idcebbf197db2cbe9ebe8b88be8c690ae7440bc62
Reviewed-on: https://chromium-review.googlesource.com/902774Reviewed-by: Stephen Lanham <slan@chromium.org>
Reviewed-by: Sergey Volk <servolk@chromium.org>
Commit-Queue: Linkun Chen <lkchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534741}

chromecast/browser/cast_browser_main_parts.cc

@@ -395,7 +395,13 @@ void CastBrowserMainParts::ToolkitInitialized() {
   // the background (resources have not yet been granted to cast) since it
   // prevents the long delay the user would have seen on first rendering. Note
   // that future calls to FcInit() are safe no-ops per the FontConfig interface.
+  FcChar8 bundle_dir[] = "fonts/";
+
   FcInit();
+
+  if (FcConfigAppFontAddDir(nullptr, bundle_dir) == FcFalse) {
+    LOG(ERROR) << "Cannot load fonts from " << bundle_dir;
+  }
 #endif
 }