mac: Periodically shim new malloc zones immediately after startup.

base/allocator/allocator_interception_mac.mm

Index: base/allocator/allocator_interception_mac.mm
diff --git a/base/allocator/allocator_interception_mac.mm b/base/allocator/allocator_interception_mac.mm
index 87c882a19cb8e5214610857237c50f8a6db41659..e155b971d1cbd9914c4f0ece970d7c0244c248a2 100644
--- a/base/allocator/allocator_interception_mac.mm
+++ b/base/allocator/allocator_interception_mac.mm
@@ -30,11 +30,15 @@
 #include "base/allocator/allocator_shim.h"
 #include "base/allocator/features.h"
 #include "base/allocator/malloc_zone_functions_mac.h"
+#include "base/base_switches.h"
+#include "base/bind.h"
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/mach_logging.h"
 #include "base/process/memory.h"
 #include "base/scoped_clear_errno.h"
+#include "base/threading/sequenced_task_runner_handle.h"
 #include "build/build_config.h"
 #include "third_party/apple_apsl/CFBase.h"
 
@@ -498,5 +502,41 @@ void InterceptAllocationsMac() {
                            reinterpret_cast<IMP>(oom_killer_allocWithZone));
 }
 
+namespace {
+
+void ShimNewMallocZones(base::Time end_time, base::TimeDelta delay) {
+  StoreFunctionsForAllZones();
+
+  // Use the functions for the default zone as a template to replace those
+  // new zones.
+  ChromeMallocZone* default_zone =
+      reinterpret_cast<ChromeMallocZone*>(malloc_default_zone());
+  DCHECK(IsMallocZoneAlreadyStored(default_zone));
+
+  MallocZoneFunctions new_functions;
+  StoreZoneFunctions(default_zone, &new_functions);
+  ReplaceFunctionsForStoredZones(&new_functions);
+
+  if (base::Time::Now() > end_time)
+    return;
+
+  base::TimeDelta next_delay = delay * 2;
+  SequencedTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE, base::Bind(&ShimNewMallocZones, end_time, next_delay), delay);
+}
+
+}  // namespace
+
+void PeriodicallyShimNewMallocZones() {
+  if (!CommandLine::InitializedForCurrentProcess() ||
+      !CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableHeapProfiling)) {
+    return;
+  }
+  base::Time end_time = base::Time::Now() + base::TimeDelta::FromMinutes(1);
+  base::TimeDelta initial_delay = base::TimeDelta::FromSeconds(1);
+  ShimNewMallocZones(end_time, initial_delay);
+}
+
 }  // namespace allocator
 }  // namespace base