base: Remove DiscardableMemoryMach.

base/memory/discardable_memory.h

 // Copyright (c) 2013 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.
 
 #ifndef BASE_MEMORY_DISCARDABLE_MEMORY_H_
 #define BASE_MEMORY_DISCARDABLE_MEMORY_H_
 
 #include <string>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace base {
 
 enum DiscardableMemoryType {
   DISCARDABLE_MEMORY_TYPE_NONE,
-  DISCARDABLE_MEMORY_TYPE_MACH,
   DISCARDABLE_MEMORY_TYPE_SHMEM
 };
 
 enum DiscardableMemoryLockStatus {
   DISCARDABLE_MEMORY_LOCK_STATUS_FAILED,
   DISCARDABLE_MEMORY_LOCK_STATUS_PURGED,
   DISCARDABLE_MEMORY_LOCK_STATUS_SUCCESS
 };
 
 // Platform abstraction for discardable memory. DiscardableMemory is used to
@@ skipping 69 matching lines @@
   virtual void Unlock() = 0;
 
   // Returns the memory address held by this object. The object must be locked
   // before calling this. Otherwise, this will cause a DCHECK error.
   virtual void* Memory() const = 0;
 };
 
 }  // namespace base
 
 #endif  // BASE_MEMORY_DISCARDABLE_MEMORY_H_