Use mach_override to intercept all newly registered malloc zones.

base/BUILD.gn

 # Copyright (c) 2013 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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 1103 matching lines @@
     "//build/config:precompiled_headers",
   ]
 
   deps = [
     "//base/allocator",
     "//base/allocator:features",
     "//base/third_party/dynamic_annotations",
     "//third_party/modp_b64",
   ]
 
+  if (is_mac) {
+    deps += [ "//third_party/mach_override" ]
+  }
+
   public_deps = [
     ":base_paths",
     ":base_static",
     ":build_date",
     ":debugging_flags",
   ]
 
   # Needed for <atomic> if using newer C++ library than sysroot
   if (!use_sysroot && (is_android || (is_linux && !is_chromecast))) {
     libs = [ "atomic" ]
@@ skipping 752 matching lines @@
     configs += [ "//build/config/compiler:enable_arc" ]
     deps = [
       ":base",
       "//testing/gtest",
     ]
   }
 }
 
 test("base_unittests") {
   sources = [
+    "allocator/allocator_interception_mac_unittest.cc",
     "allocator/malloc_zone_functions_mac_unittest.cc",
     "allocator/tcmalloc_unittest.cc",
     "android/application_status_listener_unittest.cc",
     "android/content_uri_utils_unittest.cc",
     "android/jni_android_unittest.cc",
     "android/jni_array_unittest.cc",
     "android/jni_string_unittest.cc",
     "android/library_loader/library_prefetcher_unittest.cc",
     "android/path_utils_unittest.cc",
     "android/scoped_java_ref_unittest.cc",
@@ skipping 758 matching lines @@
 }
 
 fuzzer_test("base_json_correctness_fuzzer") {
   sources = [
     "json/correctness_fuzzer.cc",
   ]
   deps = [
     ":base",
   ]
 }