Replace our homegrown ARRAY_SIZE() with Chrome's arraysize().

test/cctest/test-object-observe.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 235 matching lines @@
       if (!expectations[i].old_value.IsEmpty()) {
         CHECK(expectations[i].old_value->Equals(
             recordObj->Get(String::NewFromUtf8(isolate, "oldValue"))));
       }
     }
   }
 }
 
 #define EXPECT_RECORDS(records, expectations)                \
   ExpectRecords(CcTest::isolate(), records, expectations, \
-                ARRAY_SIZE(expectations))
+                arraysize(expectations))
 
 TEST(APITestBasicMutation) {
   v8::Isolate* v8_isolate = CcTest::isolate();
   HandleScope scope(v8_isolate);
   LocalContext context(v8_isolate);
   Handle<Object> obj = Handle<Object>::Cast(CompileRun(
       "var records = [];"
       "var obj = {};"
       "function observer(r) { [].push.apply(records, r); };"
       "Object.observe(obj, observer);"
@@ skipping 435 matching lines @@
                             notifier);
     CompileRun("var obj2 = {};"
                "var notifier2 = Object.getNotifier(obj2);"
                "notifier2.performChange.call("
                    "notifier, 'foo', function(){})");
   }
 
   CcTest::isolate()->ContextDisposedNotification();
   CheckSurvivingGlobalObjectsCount(1);
 }