Move the canonical empty context to the VM isolate.

runtime/vm/object_store.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_OBJECT_STORE_H_
 #define RUNTIME_VM_OBJECT_STORE_H_
 
 #include "vm/object.h"
 
 namespace dart {
@@ skipping 323 matching lines @@
   }
 
   RawGrowableObjectArray* resume_capabilities() const {
     return resume_capabilities_;
   }
 
   RawGrowableObjectArray* exit_listeners() const { return exit_listeners_; }
 
   RawGrowableObjectArray* error_listeners() const { return error_listeners_; }
 
-  RawContext* empty_context() const { return empty_context_; }
-  void set_empty_context(const Context& value) { empty_context_ = value.raw(); }
-
   RawInstance* stack_overflow() const { return stack_overflow_; }
   void set_stack_overflow(const Instance& value) {
     stack_overflow_ = value.raw();
   }
 
   RawInstance* out_of_memory() const { return out_of_memory_; }
   void set_out_of_memory(const Instance& value) {
     out_of_memory_ = value.raw();
   }
 
@@ skipping 205 matching lines @@
   V(RawLibrary*, typed_data_library_)                                          \
   V(RawLibrary*, _vmservice_library_)                                          \
   V(RawGrowableObjectArray*, libraries_)                                       \
   V(RawArray*, libraries_map_)                                                 \
   V(RawGrowableObjectArray*, closure_functions_)                               \
   V(RawGrowableObjectArray*, pending_classes_)                                 \
   V(RawGrowableObjectArray*, pending_deferred_loads_)                          \
   V(RawGrowableObjectArray*, resume_capabilities_)                             \
   V(RawGrowableObjectArray*, exit_listeners_)                                  \
   V(RawGrowableObjectArray*, error_listeners_)                                 \
-  V(RawContext*, empty_context_)                                               \
   V(RawInstance*, stack_overflow_)                                             \
   V(RawInstance*, out_of_memory_)                                              \
   V(RawUnhandledException*, preallocated_unhandled_exception_)                 \
   V(RawStackTrace*, preallocated_stack_trace_)                                 \
   V(RawFunction*, lookup_port_handler_)                                        \
   V(RawTypedData*, empty_uint32_array_)                                        \
   V(RawFunction*, handle_message_function_)                                    \
   V(RawFunction*, simple_instance_of_function_)                                \
   V(RawFunction*, simple_instance_of_true_function_)                           \
   V(RawFunction*, simple_instance_of_false_function_)                          \
@@ skipping 37 matching lines @@
 
   friend class Serializer;
   friend class Deserializer;
 
   DISALLOW_COPY_AND_ASSIGN(ObjectStore);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_OBJECT_STORE_H_