Add a check that weak object handle is not in NEAR_DEATH state after weak callback invocation.

src/profile-generator.cc

 // Copyright 2010 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 56 matching lines @@
   token_locations_.Add(handle.location());
   token_removed_.Add(false);
   return token_locations_.length() - 1;
 }
 
 
 void TokenEnumerator::TokenRemovedCallback(v8::Persistent<v8::Value> handle,
                                            void* parameter) {
   reinterpret_cast<TokenEnumerator*>(parameter)->TokenRemoved(
       Utils::OpenHandle(*handle).location());
+  handle.Dispose();
 }
 
 
 void TokenEnumerator::TokenRemoved(Object** token_location) {
   for (int i = 0; i < token_locations_.length(); ++i) {
     if (token_locations_[i] == token_location && !token_removed_[i]) {
       token_removed_[i] = true;
       return;
     }
   }
@@ skipping 1733 matching lines @@
     HeapEntry* entry = added_entries[i];
     if (entry->painted_reachable())
       diff->AddAddedEntry(entry);
   }
   return diff;
 }
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_LOGGING_AND_PROFILING