Use Object::null_instance and Object::null_function and do not create Handles everytime.

runtime/vm/object.cc

 // 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.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 7231 matching lines @@
   } else {
     result.SetOffset(0);
   }
   result.set_is_final(is_final);
   result.set_is_const(is_const);
   result.set_is_reflectable(is_reflectable);
   result.set_is_double_initialized(false);
   result.set_owner(owner);
   result.set_token_pos(token_pos);
   result.set_has_initializer(false);
-  result.set_initializer(Function::Handle());
   result.set_is_unboxing_candidate(true);
   result.set_guarded_cid(FLAG_use_field_guards ? kIllegalCid : kDynamicCid);
   result.set_is_nullable(FLAG_use_field_guards ? false : true);
   result.set_guarded_list_length_in_object_offset(Field::kUnknownLengthOffset);
   // Presently, we only attempt to remember the list length for final fields.
   if (is_final && FLAG_use_field_guards) {
     result.set_guarded_list_length(Field::kUnknownFixedLength);
   } else {
     result.set_guarded_list_length(Field::kNoFixedLength);
   }
-  result.set_dependent_code(Object::null_array());
   return result.raw();
 }
 
 
 
 RawField* Field::Clone(const Class& new_owner) const {
   Field& clone = Field::Handle();
   clone ^= Object::Clone(*this, Heap::kOld);
   const Class& owner = Class::Handle(this->owner());
   const PatchClass& clone_owner =
       PatchClass::Handle(PatchClass::New(new_owner, owner));
   clone.set_owner(clone_owner);
-  clone.set_dependent_code(Object::null_array());
   if (!clone.is_static()) {
     clone.SetOffset(0);
   }
   if (new_owner.NumTypeParameters() > 0) {
     // Adjust the field type to refer to type parameters of the new owner.
     AbstractType& type = AbstractType::Handle(clone.type());
     type ^= type.CloneUninstantiated(new_owner);
     clone.set_type(type);
   }
   return clone.raw();
@@ skipping 3213 matching lines @@
                                      bool deferred_load,
                                      const Library& importer) {
   const LibraryPrefix& result = LibraryPrefix::Handle(LibraryPrefix::New());
   result.set_name(name);
   result.set_num_imports(0);
   result.set_importer(importer);
   result.StoreNonPointer(&result.raw_ptr()->is_deferred_load_, deferred_load);
   result.StoreNonPointer(&result.raw_ptr()->is_loaded_, !deferred_load);
   result.set_imports(Array::Handle(Array::New(kInitialSize)));
   result.AddImport(import);
-  result.set_dependent_code(Object::null_array());
   return result.raw();
 }
 
 
 void LibraryPrefix::set_name(const String& value) const {
   ASSERT(value.IsSymbol());
   StorePointer(&raw_ptr()->name_, value.raw());
 }
 
 
@@ skipping 10847 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart