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

test/cctest/test-checks.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/checks.h"
 
 #include "test/cctest/cctest.h"
 
 
 TEST(CheckEqualsZeroAndMinusZero) {
   CHECK_EQ(0.0, 0.0);
   CHECK_NE(0.0, -0.0);
   CHECK_NE(-0.0, 0.0);
   CHECK_EQ(-0.0, -0.0);
 }
 
 
 TEST(CheckEqualsReflexivity) {
   double inf = V8_INFINITY;
   double nan = v8::base::OS::nan_value();
   double constants[] = {-nan, -inf, -3.1415, -1.0,   -0.1, -0.0,
                         0.0,  0.1,  1.0,     3.1415, inf,  nan};
-  for (size_t i = 0; i < ARRAY_SIZE(constants); ++i) {
+  for (size_t i = 0; i < arraysize(constants); ++i) {
     CHECK_EQ(constants[i], constants[i]);
   }
 }