Use DiscardableMemoryManager on Android.

base/memory/discardable_memory_mac.cc

 // 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.
 
 #include "base/memory/discardable_memory.h"
 
 #include <mach/mach.h>
 #include <sys/mman.h>
 
 #include "base/basictypes.h"
@@ skipping 129 matching lines @@
 
       return memory.PassAs<DiscardableMemory>();
     }
   }
 
   NOTREACHED();
   return scoped_ptr<DiscardableMemory>();
 }
 
 // static
-bool DiscardableMemory::PurgeForTestingSupported() {
-  return true;
+bool DiscardableMemory::PurgeForTestingSupported(DiscardableMemoryType type) {
+  switch (type) {
+    case DISCARDABLE_MEMORY_TYPE_EMULATED:
+    case DISCARDABLE_MEMORY_TYPE_MAC:
+      return true;
+    default:
+      return false;
+  }
 }
 
 // static
-void DiscardableMemory::PurgeForTesting() {
-  int state = 0;
-  vm_purgable_control(mach_task_self(), 0, VM_PURGABLE_PURGE_ALL, &state);
-  internal::DiscardableMemoryEmulated::PurgeForTesting();
+void DiscardableMemory::PurgeForTesting(DiscardableMemoryType type) {
+  switch (type) {
+    case DISCARDABLE_MEMORY_TYPE_EMULATED:
+      internal::DiscardableMemoryEmulated::PurgeForTesting();
+      return;
+    case DISCARDABLE_MEMORY_TYPE_MAC: {
+      int state = 0;
+      vm_purgable_control(mach_task_self(), 0, VM_PURGABLE_PURGE_ALL, &state);
+      internal::DiscardableMemoryEmulated::PurgeForTesting();
+      return;
+    }
+    default:
+      NOTREACHED();
+  }
 }
 
 }  // namespace base