Add Isolate::DiscardThreadSpecificMetadata method to embedder API.

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 5472 matching lines @@
    */
   void Exit();
 
   /**
    * Disposes the isolate.  The isolate must not be entered by any
    * thread to be disposable.
    */
   void Dispose();
 
   /**
+   * Discards all V8 thread-specific data for the Isolate. Should be used
+   * if a thread is terminating and it has used an Isolate that will outlive
+   * the thread -- all thread-specific data for an Isolate is discarded when
+   * an Isolate is disposed so this call is pointless if an Isolate is about
+   * to be Disposed.
+   */
+  void DiscardThreadSpecificMetadata();
+
+  /**
    * Associate embedder-specific data with the isolate. |slot| has to be
    * between 0 and GetNumberOfDataSlots() - 1.
    */
   V8_INLINE void SetData(uint32_t slot, void* data);
 
   /**
    * Retrieve embedder-specific data from the isolate.
    * Returns NULL if SetData has never been called for the given |slot|.
    */
   V8_INLINE void* GetData(uint32_t slot);
@@ skipping 2971 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_