Introduce object visitor to estimate the size of a native context.

include/v8.h

 // 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.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 6644 matching lines @@
   bool IsCodeGenerationFromStringsAllowed();
 
   /**
    * Sets the error description for the exception that is thrown when
    * code generation from strings is not allowed and 'eval' or the 'Function'
    * constructor are called.
    */
   void SetErrorMessageForCodeGenerationFromStrings(Local<String> message);
 
   /**
+   * Estimate the memory in bytes retained by this context.
+   */
+  size_t EstimatedSize();
+
+  /**
    * Stack-allocated class which sets the execution context for all
    * operations executed within a local scope.
    */
   class Scope {
    public:
     explicit V8_INLINE Scope(Local<Context> context) : context_(context) {
       context_->Enter();
     }
     V8_INLINE ~Scope() { context_->Exit(); }
 
@@ skipping 1637 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_