Use mach_override to intercept all newly registered malloc zones.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index c9bb0ea2023f64dd7f7b2446119c543f8542a9c7..fcdb107d3d213b1bafe5811a4cf51e72d55b4997 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1121,6 +1121,10 @@ component("base") {
     "//third_party/modp_b64",
   ]
 
+  if (is_mac) {
+    deps += [ "//third_party/mach_override" ]
+  }
+
   public_deps = [
     ":base_paths",
     ":base_static",
@@ -1893,6 +1897,7 @@ if (is_ios || is_mac) {
 
 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",