mac: Several minor fixes to allocator shim.

base/allocator/malloc_zone_functions_mac_unittest.cc

 // Copyright 2017 The Chromium 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 "base/allocator/malloc_zone_functions_mac.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace allocator {
 
 class MallocZoneFunctionsTest : public testing::Test {
  protected:
-  void SetUp() override { ClearAllMallocZonesForTesting(); }
+  void TearDown() override { ClearAllMallocZonesForTesting(); }
 };
 
 TEST_F(MallocZoneFunctionsTest, TestDefaultZoneMallocFree) {
   ChromeMallocZone* malloc_zone =
       reinterpret_cast<ChromeMallocZone*>(malloc_default_zone());
   StoreMallocZone(malloc_zone);
   int* test = reinterpret_cast<int*>(
       g_malloc_zones[0].malloc(malloc_default_zone(), 33));
   test[0] = 1;
   test[1] = 2;
@@ skipping 24 matching lines @@
     memcpy(&zone, malloc_default_zone(), sizeof(ChromeMallocZone));
     StoreMallocZone(&zone);
   }
 
   int max_zone_count = kMaxZoneCount;
   EXPECT_EQ(max_zone_count, GetMallocZoneCountForTesting());
 }
 
 }  // namespace allocator
 }  // namespace base