More memory stats code cleanup:...

base/process_util_mac.mm

 // Copyright (c) 2008 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/process_util.h"
 
 #import <Cocoa/Cocoa.h>
 #include <crt_externs.h>
+#include <mach/mach.h>
 #include <mach/mach_init.h>
 #include <mach/task.h>
 #include <spawn.h>
 #include <sys/sysctl.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 
 #include <string>
 
 #include "base/eintr_wrapper.h"
@@ skipping 186 matching lines @@
 
 void ProcessMetrics::GetCommittedKBytes(CommittedKBytes* usage) const {
 }
 
 bool ProcessMetrics::GetWorkingSetKBytes(WorkingSetKBytes* ws_usage) const {
   return false;
 }
 
 // ------------------------------------------------------------------------
 
+// Bytes committed by the system.
+size_t GetSystemCommitCharge() {
+  host_name_port_t host = mach_host_self();
+  mach_msg_type_number_t count = HOST_VM_INFO_COUNT;
+  vm_statistics_data_t data;
+  kern_return_t kr = host_statistics(host, HOST_VM_INFO,
+                                     reinterpret_cast<host_info_t>(&data),
+                                     &count);
+  if (kr)
+    LOG(ERROR) << "Failed to fetch host statistics.";
+    return 0;
+
+  vm_size_t page_size;
+  kr = host_page_size(host, &page_size);
+  if (kr)
+    LOG(ERROR) << "Failed to fetch host page size.";
+    return 0;
+
+  return (data.active_count * page_size) / 1024;
+}
+
 }  // namespace base