src: use global SealHandleScope

Helps to find Handle leaks in Debug mode.

PR-URL: https://github.com/iojs/io.js/pull/1395
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

src/node.cc

@@ -101,6 +101,7 @@ using v8::ObjectTemplate;
 using v8::Promise;
 using v8::PromiseRejectMessage;
 using v8::PropertyCallbackInfo;
+using v8::SealHandleScope;
 using v8::String;
 using v8::TryCatch;
 using v8::Uint32;
@@ -3836,6 +3837,8 @@ static void StartNodeInstance(void* arg) {
     if (instance_data->use_debug_agent())
       EnableDebug(env);
 
+    {
+      SealHandleScope seal(isolate);
       bool more;
       do {
         v8::platform::PumpMessageLoop(default_platform, isolate);
@@ -3852,6 +3855,7 @@ static void StartNodeInstance(void* arg) {
             more = true;
         }
       } while (more == true);
+    }
 
     int exit_code = EmitExit(env);
     if (instance_data->is_main())