Fix some potential Mach port leaks from mach_host_self using a new ScopedMachPort class.

base/sys_info_ios.mm

 // Copyright (c) 2012 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/sys_info.h"
 
 #import <UIKit/UIKit.h>
 #include <mach/mach.h>
 #include <sys/sysctl.h>
 #include <sys/types.h>
 
 #include "base/logging.h"
+#include "base/mac/scoped_mach_port.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/sys_string_conversions.h"
 
 namespace base {
 
 // static
 std::string SysInfo::OperatingSystemName() {
   base::mac::ScopedNSAutoreleasePool pool;
   // Examples of returned value: 'iPhone OS' on iPad 5.1.1
   // and iPhone 5.1.1.
@@ skipping 25 matching lines @@
   if (length >= 3)
     *bugfix_version = [[version_info objectAtIndex:2] intValue];
   else
     *bugfix_version = 0;
 }
 
 // static
 int64 SysInfo::AmountOfPhysicalMemory() {
   struct host_basic_info hostinfo;
   mach_msg_type_number_t count = HOST_BASIC_INFO_COUNT;
-  int result = host_info(mach_host_self(),
+  base::mac::ScopedMachPort<host_name_port_t> host(mach_host_self());
+  int result = host_info(host,
                          HOST_BASIC_INFO,
                          reinterpret_cast<host_info_t>(&hostinfo),
                          &count);
   if (result != KERN_SUCCESS) {
     NOTREACHED();
     return 0;
   }
   DCHECK_EQ(HOST_BASIC_INFO_COUNT, count);
   return static_cast<int64>(hostinfo.max_mem);
 }
 
 // static
 std::string SysInfo::CPUModelName() {
   char name[256];
   size_t len = arraysize(name);
   if (sysctlbyname("machdep.cpu.brand_string", &name, &len, NULL, 0) == 0)
     return name;
   return std::string();
 }
 
 }  // namespace base