Revert of base: Make shared memory backed by Mach primitives by default.

base/memory/shared_memory_unittest.cc

 // 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/atomicops.h"
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/shared_memory.h"
 #include "base/process/kill.h"
 #include "base/rand_util.h"
@@ skipping 455 matching lines @@
 // This test is not applicable for iOS (crbug.com/399384).
 #if !defined(OS_IOS)
 // Create a shared memory object, mmap it, and mprotect it to PROT_EXEC.
 TEST(SharedMemoryTest, AnonymousExecutable) {
   const uint32 kTestSize = 1 << 16;
 
   SharedMemory shared_memory;
   SharedMemoryCreateOptions options;
   options.size = kTestSize;
   options.executable = true;
-#if defined(OS_MACOSX) && !defined(OS_IOS)
-  // The Mach functionality is tested in shared_memory_mac_unittest.cc.
-  options.type = SharedMemoryHandle::POSIX;
-#endif
 
   EXPECT_TRUE(shared_memory.Create(options));
   EXPECT_TRUE(shared_memory.Map(shared_memory.requested_size()));
 
   EXPECT_EQ(0, mprotect(shared_memory.memory(), shared_memory.requested_size(),
                         PROT_READ | PROT_EXEC));
 }
 #endif  // !defined(OS_IOS)
 
 // Android supports a different permission model than POSIX for its "ashmem"
@@ skipping 155 matching lines @@
   memory.Close();
   SharedMemoryProcessTest::CleanUp();
 }
 
 MULTIPROCESS_TEST_MAIN(SharedMemoryTestMain) {
   return SharedMemoryProcessTest::TaskTestMain();
 }
 #endif  // !defined(OS_IOS) && !defined(OS_ANDROID) && !defined(OS_MACOSX)
 
 }  // namespace base