Revert of Use DiscardableMemoryManager on Android.

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_ASHMEM,
+  DISCARDABLE_MEMORY_TYPE_ANDROID,
   DISCARDABLE_MEMORY_TYPE_MAC,
   DISCARDABLE_MEMORY_TYPE_EMULATED,
   DISCARDABLE_MEMORY_TYPE_MALLOC
 };
 
 enum DiscardableMemoryLockStatus {
   DISCARDABLE_MEMORY_LOCK_STATUS_FAILED,
   DISCARDABLE_MEMORY_LOCK_STATUS_PURGED,
   DISCARDABLE_MEMORY_LOCK_STATUS_SUCCESS
 };
@@ skipping 77 matching lines @@
   // Unlocks the memory so that it can be purged by the system. Must be called
   // after every successful lock call.
   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;
 
   // Testing utility calls.
 
+  // Check whether a purge of all discardable memory in the system is supported.
+  // Use only for testing!
+  static bool PurgeForTestingSupported();
+
   // Purge all discardable memory in the system. This call has global effects
   // across all running processes, so it should only be used for testing!
   static void PurgeForTesting();
 };
 
 }  // namespace base
 
 #endif  // BASE_MEMORY_DISCARDABLE_MEMORY_H_