1 files changed, 48 insertions, 0 deletions
diff --git a/chromium/media/audio/scoped_task_runner_observer.cc b/chromium/media/audio/scoped_task_runner_observer.cc
new file mode 100644
index 00000000000..9f4eac28511
--- /dev/null
+++ b/chromium/media/audio/scoped_task_runner_observer.cc
@@ -0,0 +1,48 @@
+// Copyright (c) 2012 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 "media/audio/scoped_task_runner_observer.h"
+
+#include "base/bind.h"
+#include "base/synchronization/waitable_event.h"
+
+namespace media {
+
+ScopedTaskRunnerObserver::ScopedTaskRunnerObserver(
+    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
+    : task_runner_(task_runner) {
+  ObserveLoopDestruction(true, NULL);
+}
+
+ScopedTaskRunnerObserver::~ScopedTaskRunnerObserver() {
+  ObserveLoopDestruction(false, NULL);
+}
+
+void ScopedTaskRunnerObserver::ObserveLoopDestruction(
+    bool enable,
+    base::WaitableEvent* done) {
+  // Note: |done| may be NULL.
+  if (task_runner_->BelongsToCurrentThread()) {
+    base::MessageLoop* loop = base::MessageLoop::current();
+    if (enable) {
+      loop->AddDestructionObserver(this);
+    } else {
+      loop->RemoveDestructionObserver(this);
+    }
+  } else {
+    base::WaitableEvent event(false, false);
+    if (task_runner_->PostTask(FROM_HERE,
+            base::Bind(&ScopedTaskRunnerObserver::ObserveLoopDestruction,
+                       base::Unretained(this), enable, &event))) {
+      event.Wait();
+    } else {
+      // The message loop's thread has already terminated, so no need to wait.
+    }
+  }
+
+  if (done)
+    done->Signal();
+}
+
+}  // namespace media.