mac: Add auto-close and share-read-only functionality to SharedMemory.

ipc/test_util_mac.cc

 // Copyright 2015 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 "ipc/test_util_mac.h"
 
+#include <mach/mach_vm.h>
 #include <servers/bootstrap.h>
 
 #include "base/mac/mach_logging.h"
 #include "base/mac/scoped_mach_port.h"
 #include "base/rand_util.h"
 #include "base/strings/stringprintf.h"
 
 namespace {
 
 // Structs used to pass a Mach port over mach_msg().
@@ skipping 90 matching lines @@
                                         MACH_PORT_RIGHT_SEND, &ref_count);
   MACH_CHECK(kr == KERN_SUCCESS, kr) << "GetRefCount";
   return ref_count;
 }
 
 void IncrementMachRefCount(mach_port_name_t name, mach_port_right_t right) {
   kern_return_t kr = mach_port_mod_refs(mach_task_self(), name, right, 1);
   MACH_CHECK(kr == KERN_SUCCESS, kr) << "GetRefCount";
 }
 
+bool GetMachProtections(void* address, size_t size, int* current, int* max) {
+  vm_region_info_t region_info;
+  mach_vm_address_t mem_address = reinterpret_cast<mach_vm_address_t>(address);
+  mach_vm_size_t mem_size = size;
+  vm_region_basic_info_64 basic_info;
+
+  region_info = reinterpret_cast<vm_region_recurse_info_t>(&basic_info);
+  vm_region_flavor_t flavor = VM_REGION_BASIC_INFO_64;
+  memory_object_name_t memory_object;
+  mach_port_t ctype;
+
+  kern_return_t kr =
+      mach_vm_region(mach_task_self(), &mem_address, &mem_size, flavor,
+                     region_info, &memory_object, &ctype);
+  if (kr != KERN_SUCCESS) {
+    LOG(ERROR) << "Failed to get region info.";
+    return false;
+  }
+
+  *current = basic_info.protection;
+  *max = basic_info.max_protection;
+  return true;
+}
+
 }  // namespace IPC