Remove TLS access for current Zone.

src/isolate.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 1376 matching lines @@
  private:
   StackGuard* stack_guard_;
 };
 
 
 // Temporary macros for accessing current isolate and its subobjects.
 // They provide better readability, especially when used a lot in the code.
 #define HEAP (v8::internal::Isolate::Current()->heap())
 #define FACTORY (v8::internal::Isolate::Current()->factory())
 #define ISOLATE (v8::internal::Isolate::Current())
-#define ZONE (v8::internal::Isolate::Current()->zone())
 #define LOGGER (v8::internal::Isolate::Current()->logger())
 
 
 // Tells whether the global context is marked with out of memory.
 inline bool Context::has_out_of_memory() {
   return global_context()->out_of_memory()->IsTrue();
 }
 
 
 // Mark the global context with out of memory.
 inline void Context::mark_out_of_memory() {
   global_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_