Add an API to let the embedder associate arbitrary data with a v8::Context.

include/v8.h

 // Copyright 2012 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3704 matching lines @@
 
   /**
    * Associate an additional data object with the context. This is mainly used
    * with the debugger to provide additional information on the context through
    * the debugger API.
    */
   void SetData(Handle<Value> data);
   Local<Value> GetData();
 
   /**
+   * Associate an opaque pointer with the context. This pointer can be used by
+   * the embedder to associate additional state with the context.
+   */
+  void SetEmbedderData(void* data);
+  void* GetEmbedderData();
+
+  /**
    * Control whether code generation from strings is allowed. Calling
    * this method with false will disable 'eval' and the 'Function'
    * constructor for code running in this context. If 'eval' or the
    * 'Function' constructor are used an exception will be thrown.
    *
    * If code generation from strings is not allowed the
    * V8::AllowCodeGenerationFromStrings callback will be invoked if
    * set before blocking the call to 'eval' or the 'Function'
    * constructor. If that callback returns true, the call will be
    * allowed, otherwise an exception will be thrown. If no callback is
@@ skipping 919 matching lines @@
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_