Remove support for Object.observe

test/mjsunit/es7/object-observe-debug-event.js

-// 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.
-
-// Flags: --harmony-object-observe
-// Flags: --expose-debug-as debug
-
-Debug = debug.Debug;
-
-var base_id = -1;
-var exception = null;
-var expected = [
-  "enqueue #1",
-  "willHandle #1",
-  "didHandle #1",
-];
-
-function assertLog(msg) {
-  print(msg);
-  assertTrue(expected.length > 0);
-  assertEquals(expected.shift(), msg);
-  if (!expected.length) {
-    Debug.setListener(null);
-  }
-}
-
-function listener(event, exec_state, event_data, data) {
-  if (event != Debug.DebugEvent.AsyncTaskEvent) return;
-  try {
-    if (base_id < 0)
-      base_id = event_data.id();
-    var id = event_data.id() - base_id + 1;
-    assertEquals("Object.observe", event_data.name());
-    assertLog(event_data.type() + " #" + id);
-  } catch (e) {
-    print(e + e.stack)
-    exception = e;
-  }
-}
-
-Debug.setListener(listener);
-
-var obj = {};
-Object.observe(obj, function(changes) {
-  print(change.type + " " + change.name + " " + change.oldValue);
-});
-
-obj.foo = 1;
-obj.zoo = 2;
-obj.foo = 3;
-
-assertNull(exception);