Remove more dead code after Object.observe removal

src/isolate-inl.h

 // Copyright 2015 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_ISOLATE_INL_H_
 #define V8_ISOLATE_INL_H_
 
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 
@@ skipping 55 matching lines @@
   thread_local_top_.scheduled_exception_ = heap_.the_hole_value();
 }
 
 
 bool Isolate::is_catchable_by_javascript(Object* exception) {
   return exception != heap()->termination_exception();
 }
 
 
 Handle<JSGlobalObject> Isolate::global_object() {
-  return Handle<JSGlobalObject>(context()->global_object(), this);
+  return handle(context()->global_object(), this);
+}
+
+Handle<JSObject> Isolate::global_proxy() {
+  return handle(context()->global_proxy(), this);
 }
 
 
 Isolate::ExceptionScope::ExceptionScope(Isolate* isolate)
     : isolate_(isolate),
       pending_exception_(isolate_->pending_exception(), isolate_) {}
 
 
 Isolate::ExceptionScope::~ExceptionScope() {
   isolate_->set_pending_exception(*pending_exception_);
 }
 
 
 #define NATIVE_CONTEXT_FIELD_ACCESSOR(index, type, name) \
   Handle<type> Isolate::name() {                         \
     return Handle<type>(native_context()->name(), this); \
   }                                                      \
   bool Isolate::is_##name(type* value) {                 \
     return native_context()->is_##name(value);           \
   }
 NATIVE_CONTEXT_FIELDS(NATIVE_CONTEXT_FIELD_ACCESSOR)
 #undef NATIVE_CONTEXT_FIELD_ACCESSOR
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_INL_H_