Back out r269483 and the line of fixes that followed it.

base/mac/scoped_mach_vm.cc

 // Copyright 2014 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/mac/scoped_mach_vm.h"
 
-#if defined(OS_IOS)
-#define mach_vm_address_t vm_address_t
-#define mach_vm_size_t vm_size_t
-#define mach_vm_deallocate vm_deallocate
-#endif  // OS_IOS
-
 namespace base {
 namespace mac {
 
 void ScopedMachVM::reset(mach_vm_address_t address, mach_vm_size_t size) {
   DCHECK(address % PAGE_SIZE == 0);
   DCHECK(size % PAGE_SIZE == 0);
 
   if (size_) {
     if (address_ < address) {
       mach_vm_deallocate(mach_task_self(),
                          address_,
                          std::min(size_, address - address_));
     }
     if (address_ + size_ > address + size) {
       mach_vm_address_t deallocate_start = std::max(address_, address + size);
       mach_vm_deallocate(mach_task_self(),
                          deallocate_start,
                          address_ + size_ - deallocate_start);
     }
   }
 
   address_ = address;
   size_ = size;
 }
 
 }  // namespace mac
 }  // namespace base