Introduce networking.cast API

chrome/browser/extensions/BUILD.gn

Index: chrome/browser/extensions/BUILD.gn
diff --git a/chrome/browser/extensions/BUILD.gn b/chrome/browser/extensions/BUILD.gn
index c07cb58308be3a3c7c8e835d7a524e58a0d53c1d..4bf0a8d4a2a6566797922b74b3ee110dc498ba9b 100644
--- a/chrome/browser/extensions/BUILD.gn
+++ b/chrome/browser/extensions/BUILD.gn
@@ -966,6 +966,10 @@ static_library("extensions") {
       "api/log_private/syslog_parser.cc",
       "api/log_private/syslog_parser.h",
       "api/messaging/native_message_host_chromeos.cc",
+      "api/networking_cast_private/chrome_networking_cast_private_delegate.cc",
+      "api/networking_cast_private/chrome_networking_cast_private_delegate.h",
+      "api/networking_cast_private/networking_cast_private_api.cc",
+      "api/networking_cast_private/networking_cast_private_api.h",
       "api/networking_private/crypto_verify_impl.cc",
       "api/networking_private/crypto_verify_impl.h",
       "api/platform_keys/platform_keys_api.cc",
@@ -1070,6 +1074,10 @@ static_library("extensions") {
 
   if (is_win || is_mac) {
     sources += [
+      "api/networking_cast_private/chrome_networking_cast_private_delegate.cc",
+      "api/networking_cast_private/chrome_networking_cast_private_delegate.h",
+      "api/networking_cast_private/networking_cast_private_api.cc",
+      "api/networking_cast_private/networking_cast_private_api.h",
       "api/networking_private/crypto_verify_impl.cc",
       "api/networking_private/crypto_verify_impl.h",
       "api/networking_private/networking_private_credentials_getter.h",