1 files changed, 52 insertions, 0 deletions
diff --git a/dom/media/systemservices/MediaTaskUtils.h b/dom/media/systemservices/MediaTaskUtils.h
new file mode 100644
index 0000000000..cbe464e015
--- /dev/null
+++ b/dom/media/systemservices/MediaTaskUtils.h
@@ -0,0 +1,52 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* 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_MediaTaskUtils_h
+#define mozilla_MediaTaskUtils_h
+
+#include "nsThreadUtils.h"
+
+// The main reason this file is separate from MediaUtils.h
+#include "base/task.h"
+
+namespace mozilla {
+namespace media {
+
+/* media::NewTaskFrom() - Create a Task from a lambda.
+ *
+ * Similar to media::NewRunnableFrom() - Create an nsRunnable from a lambda,
+ * but ignore the return value from the lambda.
+ *
+ * Prefer NS_NewRunnableFunction(), which provides a specific name, unless the
+ * lambda really must have a non-void return value that is to be ignored.
+ */
+
+template <typename OnRunType>
+class LambdaTask : public Runnable {
+ public:
+  explicit LambdaTask(OnRunType&& aOnRun)
+      : Runnable("media::LambdaTask"), mOnRun(std::move(aOnRun)) {}
+
+ private:
+  NS_IMETHOD
+  Run() override {
+    mOnRun();
+    return NS_OK;
+  }
+  OnRunType mOnRun;
+};
+
+template <typename OnRunType>
+already_AddRefed<LambdaTask<OnRunType>> NewTaskFrom(OnRunType&& aOnRun) {
+  typedef LambdaTask<OnRunType> LambdaType;
+  RefPtr<LambdaType> lambda = new LambdaType(std::forward<OnRunType>(aOnRun));
+  return lambda.forget();
+}
+
+}  // namespace media
+}  // namespace mozilla
+
+#endif  // mozilla_MediaTaskUtils_h