Add user action metric for UI DevTools http server connections

components/ui_devtools/devtools_server.cc

Index: components/ui_devtools/devtools_server.cc
diff --git a/components/ui_devtools/devtools_server.cc b/components/ui_devtools/devtools_server.cc
index a901f937e988058a5726e291691e10655ed2eae5..cde40b27e79985acc32cdd2ed78a05913c59936f 100644
--- a/components/ui_devtools/devtools_server.cc
+++ b/components/ui_devtools/devtools_server.cc
@@ -10,6 +10,7 @@
 #include "base/format_macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
+#include "base/metrics/user_metrics.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ -133,7 +134,7 @@ void UiDevToolsServer::StartServer(const std::string& address_string,
 
 // HttpServer::Delegate Implementation
 void UiDevToolsServer::OnConnect(int connection_id) {
-  NOTIMPLEMENTED();
+  base::RecordAction(base::UserMetricsAction("UI_DevTools_Connect"));
 }
 
 void UiDevToolsServer::OnHttpRequest(int connection_id,