d8 workers: fix race on quit() with context_mutex_

src/d8.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 
 // Defined when linking against shared lib on Windows.
 #if defined(USING_V8_SHARED) && !defined(V8_SHARED)
 #define V8_SHARED
 #endif
 
@@ skipping 792 matching lines @@
 
   Worker* worker =
       static_cast<Worker*>(Local<External>::Cast(this_value)->Value());
   worker->Terminate();
 }
 #endif  // !V8_SHARED
 
 
 void Shell::Quit(const v8::FunctionCallbackInfo<v8::Value>& args) {
   int exit_code = args[0]->Int32Value();
+#ifndef V8_SHARED
+  CleanupWorkers();
+#endif  // !V8_SHARED
   OnExit(args.GetIsolate());
   exit(exit_code);
 }
 
 
 void Shell::Version(const v8::FunctionCallbackInfo<v8::Value>& args) {
   args.GetReturnValue().Set(
       String::NewFromUtf8(args.GetIsolate(), V8::GetVersion()));
 }
 
@@ skipping 1607 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif