[Devtools] Allow User-Agent header override for Websockets

content/browser/devtools/devtools_agent_host_impl.cc

Index: content/browser/devtools/devtools_agent_host_impl.cc
diff --git a/content/browser/devtools/devtools_agent_host_impl.cc b/content/browser/devtools/devtools_agent_host_impl.cc
index 033f2f18bd90375c7800e59f529ff51db66ebf56..ef7ca38ba2ce0c971dc77aa9770ddd1d08a2d015 100644
--- a/content/browser/devtools/devtools_agent_host_impl.cc
+++ b/content/browser/devtools/devtools_agent_host_impl.cc
@@ -162,6 +162,10 @@ void DevToolsAgentHostImpl::SendProtocolNotification(
   SendMessageToClient(session_id_, message);
 }
 
+std::string DevToolsAgentHostImpl::GetUserAgentOverride() {
+  return "";
+}
+
 void DevToolsAgentHostImpl::HostClosed() {
   if (!client_)
     return;