1 files changed, 64 insertions, 0 deletions
diff --git a/dom/ipc/IdType.h b/dom/ipc/IdType.h
new file mode 100644
index 0000000000..ccf8b52693
--- /dev/null
+++ b/dom/ipc/IdType.h
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_IdType_h
+#define mozilla_dom_IdType_h
+
+#include "ipc/IPCMessageUtils.h"
+
+namespace IPC {
+template <typename T>
+struct ParamTraits;
+}  // namespace IPC
+
+namespace mozilla::dom {
+class BrowsingContext;
+class ContentParent;
+class BrowserParent;
+
+template <typename T>
+class IdType {
+  friend struct IPC::ParamTraits<IdType<T>>;
+
+ public:
+  IdType() : mId(0) {}
+  explicit IdType(uint64_t aId) : mId(aId) {}
+
+  operator uint64_t() const { return mId; }
+
+  IdType& operator=(uint64_t aId) {
+    mId = aId;
+    return *this;
+  }
+
+  bool operator<(const IdType& rhs) { return mId < rhs.mId; }
+
+ private:
+  uint64_t mId;
+};
+
+using TabId = IdType<BrowserParent>;
+using ContentParentId = IdType<ContentParent>;
+}  // namespace mozilla::dom
+
+namespace IPC {
+
+template <typename T>
+struct ParamTraits<mozilla::dom::IdType<T>> {
+  using paramType = mozilla::dom::IdType<T>;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.mId);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    return ReadParam(aReader, &aResult->mId);
+  }
+};
+
+}  // namespace IPC
+
+#endif  // mozilla_dom_IdType_h