base: Discardable memory types.

base/memory/discardable_memory.cc

Index: base/memory/discardable_memory.cc
diff --git a/base/memory/discardable_memory.cc b/base/memory/discardable_memory.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6d74d650e7ff1ab3ece3b85cacb1e168817a0602
--- /dev/null
+++ b/base/memory/discardable_memory.cc
@@ -0,0 +1,36 @@
+// Copyright 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 "base/lazy_instance.h"
+
+namespace base {
+namespace {
+
+struct TypeInitializedWithPreferredValue {
+  TypeInitializedWithPreferredValue() : value(DISCARDABLE_MEMORY_TYPE_NONE) {
+    std::vector<DiscardableMemoryType> supported_types;
+    DiscardableMemory::GetSupportedTypes(&supported_types);
+    DCHECK(!supported_types.empty());
+    value = supported_types.front();
+  }
+  DiscardableMemoryType value;
+};
+LazyInstance<TypeInitializedWithPreferredValue>::Leaky
+    g_discardable_memory_type = LAZY_INSTANCE_INITIALIZER;
+
+}  // namespace
+
+// static
+void DiscardableMemory::SetType(DiscardableMemoryType type) {
+  g_discardable_memory_type.Get().value = type;
+}
+
+// static
+DiscardableMemoryType DiscardableMemory::GetType() {
+  return g_discardable_memory_type.Get().value;
+}
+
+}  // namespace base