mac: Periodically shim new malloc zones immediately after startup.

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 519d13f4258d88f56fc575160a4ee603b7ab6110..9f1690e4734a1d8fdc39a796d204bd204f8f2ba2 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -10,6 +10,7 @@
 #include <utility>
 #include <vector>
 
+#include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/feature_list.h"
@@ -135,6 +136,7 @@
 #endif
 
 #if defined(OS_MACOSX)
+#include "base/allocator/allocator_interception_mac.h"
 #include "base/memory/memory_pressure_monitor_mac.h"
 #include "content/browser/bootstrap_sandbox_manager_mac.h"
 #include "content/browser/cocoa/system_hotkey_helper_mac.h"
@@ -860,6 +862,14 @@ int BrowserMainLoop::PreCreateThreads() {
   if (base::FeatureList::IsEnabled(features::kMemoryCoordinator))
     MemoryCoordinatorImpl::GetInstance()->Start();
 
+#if defined(OS_MACOSX)
+  if (base::CommandLine::InitializedForCurrentProcess() &&
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableHeapProfiling)) {
+    base::allocator::PeriodicallyShimNewMallocZones();
+  }
+#endif
+
 #if BUILDFLAG(ENABLE_PLUGINS)
   // Prior to any processing happening on the IO thread, we create the
   // plugin service as it is predominantly used from the IO thread,