Leak the JavascriptEnvironment on exit

This is to work around the bug that V8 would be waiting for background
tasks to finish on exit, while somehow it waits forever in Electron, more
about this can be found at electron#4767.

On the other handle there is actually no need to gracefully shutdown V8
on exit in the main process, we already ensured all necessary resources get
cleaned up, and it would make quitting faster.

atom/browser/atom_browser_main_parts.cc

@@ -46,6 +46,14 @@ AtomBrowserMainParts::AtomBrowserMainParts()
 }
 
 AtomBrowserMainParts::~AtomBrowserMainParts() {
+  // Leak the JavascriptEnvironment on exit.
+  // This is to work around the bug that V8 would be waiting for background
+  // tasks to finish on exit, while somehow it waits forever in Electron, more
+  // about this can be found at https://github.com/atom/electron/issues/4767.
+  // On the other handle there is actually no need to gracefully shutdown V8
+  // on exit in the main process, we already ensured all necessary resources get
+  // cleaned up, and it would make quitting faster.
+  ignore_result(js_env_.release());
 }
 
 // static
@@ -172,14 +180,6 @@ void AtomBrowserMainParts::PostMainMessageLoopRun() {
     ++iter;
     callback.Run();
   }
-
-  // Destroy JavaScript environment immediately after running destruction
-  // callbacks.
-  gc_timer_.Stop();
-  node_debugger_.reset();
-  atom_bindings_.reset();
-  node_bindings_.reset();
-  js_env_.reset();
 }
 
 }  // namespace atom