Create MetricsPrivateDelegate for metricsPrivate behavior

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 a64ac0f5ca400a0c0e0fad206debddfd39bd97b9..878f7180def0baa349786111112af9c256ef97e9 100644
--- a/extensions/browser/api/extensions_api_client.cc
+++ b/extensions/browser/api/extensions_api_client.cc
@@ -99,4 +99,8 @@ ManagementAPIDelegate* ExtensionsAPIClient::CreateManagementAPIDelegate()
   return nullptr;
 }
 
+MetricsPrivateDelegate* ExtensionsAPIClient::GetMetricsPrivateDelegate() {
+  return nullptr;
+}
+
 }  // namespace extensions