Introduce networking.cast API

extensions/browser/api/extensions_api_client.cc

Index: extensions/browser/api/extensions_api_client.cc
diff --git a/extensions/browser/api/extensions_api_client.cc b/extensions/browser/api/extensions_api_client.cc
index b9cb0756f180c9c89447be272ff43c50b4ba04e9..1d183bd97c68ff829e7ad73265ba2761f0b6b6b5 100644
--- a/extensions/browser/api/extensions_api_client.cc
+++ b/extensions/browser/api/extensions_api_client.cc
@@ -103,6 +103,11 @@ MetricsPrivateDelegate* ExtensionsAPIClient::GetMetricsPrivateDelegate() {
   return nullptr;
 }
 
+NetworkingCastPrivateDelegate*
+ExtensionsAPIClient::GetNetworkingCastPrivateDelegate() {
+  return nullptr;
+}
+
 #if defined(OS_CHROMEOS)
 NonNativeFileSystemDelegate*
 ExtensionsAPIClient::GetNonNativeFileSystemDelegate() {