discardable_memory: Using mojo IPC to replace Chrome IPC

components/discardable_memory/public/interfaces/discardable_shared_memory_manager.mojom

+// Copyright 2016 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.
+
+module discardable_memory.mojom;
+
+// This interface is used for allocating discardable shared memory from browser
+// process. For mus+ash, this service will live in mus process.
+interface DiscardableSharedMemoryManager {
+  // Allocate a locked discardable shared memory segment.
+  AllocateLockedDiscardableSharedMemory(
+      uint32 size,
+      int32 id) => (handle<shared_buffer> memory);
+  // Notify manager that a memory segment has been deleted.
+  DeletedDiscardableSharedMemory(int32 id);
+};