Remove support for Object.observe

src/transitions-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_TRANSITIONS_INL_H_
 #define V8_TRANSITIONS_INL_H_
 
 #include "src/transitions.h"
 
 namespace v8 {
@@ skipping 95 matching lines @@
 }
 
 
 #ifdef DEBUG
 bool TransitionArray::IsSpecialTransition(Name* name) {
   if (!name->IsSymbol()) return false;
   Heap* heap = name->GetHeap();
   return name == heap->nonextensible_symbol() ||
          name == heap->sealed_symbol() || name == heap->frozen_symbol() ||
          name == heap->elements_transition_symbol() ||
-         name == heap->strict_function_transition_symbol() ||
-         name == heap->observed_symbol();
+         name == heap->strict_function_transition_symbol();
 }
 #endif
 
 
 int TransitionArray::CompareKeys(Name* key1, uint32_t hash1, PropertyKind kind1,
                                  PropertyAttributes attributes1, Name* key2,
                                  uint32_t hash2, PropertyKind kind2,
                                  PropertyAttributes attributes2) {
   int cmp = CompareNames(key1, hash1, key2, hash2);
   if (cmp != 0) return cmp;
@@ skipping 48 matching lines @@
 
 void TransitionArray::SetNumberOfTransitions(int number_of_transitions) {
   DCHECK(number_of_transitions <= Capacity(this));
   set(kTransitionLengthIndex, Smi::FromInt(number_of_transitions));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TRANSITIONS_INL_H_