Add a UseCounter for Object.observe

src/runtime/runtime-observe.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 
 #include "src/arguments.h"
 #include "src/debug.h"
 #include "src/runtime/runtime-utils.h"
 
@@ skipping 70 matching lines @@
   if (isolate->has_pending_exception()) {
     isolate->ReportPendingMessages();
     isolate->clear_pending_exception();
     isolate->set_external_caught_exception(false);
   }
   return isolate->heap()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_GetObservationState) {
-  SealHandleScope shs(isolate);
+  HandleScope scope(isolate);
   DCHECK(args.length() == 0);
+  isolate->CountUsage(v8::Isolate::kObjectObserve);
   return isolate->heap()->observation_state();
 }
 
 
 static bool ContextsHaveSameOrigin(Handle<Context> context1,
                                    Handle<Context> context2) {
   return context1->security_token() == context2->security_token();
 }
 
 
@@ skipping 48 matching lines @@
 RUNTIME_FUNCTION(Runtime_GetObjectContextNotifierPerformChange) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object_info, 0);
 
   Handle<Context> context(object_info->GetCreationContext(), isolate);
   return context->native_object_notifier_perform_change();
 }
 }
 }  // namespace v8::internal