Use DiscardableMemoryManager on Android.

base/memory/discardable_memory_mac.cc

Index: base/memory/discardable_memory_mac.cc
diff --git a/base/memory/discardable_memory_mac.cc b/base/memory/discardable_memory_mac.cc
index 40a97392e955e1a740171f82ffca6f9508fa3805..3528514882282a26814178b7a11cbe837e919ac7 100644
--- a/base/memory/discardable_memory_mac.cc
+++ b/base/memory/discardable_memory_mac.cc
@@ -147,15 +147,31 @@ scoped_ptr<DiscardableMemory> DiscardableMemory::CreateLockedMemoryWithType(
 }
 
 // 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