Reintroduce runtime zone to Isolate.

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 878 matching lines @@
     return descriptor_lookup_cache_;
   }
 
   v8::ImplementationUtilities::HandleScopeData* handle_scope_data() {
     return &handle_scope_data_;
   }
   HandleScopeImplementer* handle_scope_implementer() {
     ASSERT(handle_scope_implementer_);
     return handle_scope_implementer_;
   }
+  Zone* runtime_zone() { return &runtime_zone_; }
 
   UnicodeCache* unicode_cache() {
     return unicode_cache_;
   }
 
   InnerPointerToCodeCache* inner_pointer_to_code_cache() {
     return inner_pointer_to_code_cache_;
   }
 
   ConsStringIteratorOp* write_iterator() { return write_iterator_; }
@@ skipping 354 matching lines @@
   int stack_trace_for_uncaught_exceptions_frame_limit_;
   StackTrace::StackTraceOptions stack_trace_for_uncaught_exceptions_options_;
   TranscendentalCache* transcendental_cache_;
   MemoryAllocator* memory_allocator_;
   KeyedLookupCache* keyed_lookup_cache_;
   ContextSlotCache* context_slot_cache_;
   DescriptorLookupCache* descriptor_lookup_cache_;
   v8::ImplementationUtilities::HandleScopeData handle_scope_data_;
   HandleScopeImplementer* handle_scope_implementer_;
   UnicodeCache* unicode_cache_;
+  Zone runtime_zone_;
   PreallocatedStorage in_use_list_;
   PreallocatedStorage free_list_;
   bool preallocated_storage_preallocated_;
   InnerPointerToCodeCache* inner_pointer_to_code_cache_;
   ConsStringIteratorOp* write_iterator_;
   GlobalHandles* global_handles_;
   ContextSwitcher* context_switcher_;
   ThreadManager* thread_manager_;
   RuntimeState runtime_state_;
   bool fp_stubs_generated_;
@@ skipping 219 matching lines @@
 
 // Mark the native context with out of memory.
 inline void Context::mark_out_of_memory() {
   native_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_