Move createClosure from V8PromiseCustom.cpp to V8Binding.h

Source/bindings/v8/V8Binding.h

 /*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2012 Ericsson AB. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
@@ skipping 561 matching lines @@
 
     void crashIfV8IsDead();
 
     template <class T>
     v8::Handle<T> unsafeHandleFromRawValue(const T* value)
     {
         const v8::Handle<T>* handle = reinterpret_cast<const v8::Handle<T>*>(&value);
         return *handle;
     }
 
+    // Attaches |environment| to |function| and returns it.
+    inline v8::Local<v8::Function> createClosure(v8::FunctionCallback function, v8::Handle<v8::Value> environment)
+    {
+        return v8::FunctionTemplate::New(function, environment)->GetFunction();
+    }
+
 } // namespace WebCore
 
 #endif // V8Binding_h