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diff --git a/ipc/chromium/src/chrome/common/ipc_channel_capability.h b/ipc/chromium/src/chrome/common/ipc_channel_capability.h
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+++ b/ipc/chromium/src/chrome/common/ipc_channel_capability.h
@@ -0,0 +1,61 @@
+/* -*- 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 CHROME_COMMON_IPC_CHANNEL_CAPABILITY_H_
+#define CHROME_COMMON_IPC_CHANNEL_CAPABILITY_H_
+
+#include "mozilla/ThreadSafety.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/EventTargetCapability.h"
+#include "nsISerialEventTarget.h"
+
+namespace IPC {
+
+// A thread-safety capability used in IPC channel implementations. Combines an
+// EventTargetCapability and a Mutex to allow using each independently, as well
+// as combined together.
+//
+// The ChannelCapability grants shared access if on the IOThread or if the send
+// mutex is held, and only allows exclusive access if both on the IO thread and
+// holding the send mutex. This is similar to a `MutexSingleWriter`, but more
+// flexible due to providing access to each sub-capability.
+class MOZ_CAPABILITY("channel cap") ChannelCapability {
+ public:
+  using Mutex = mozilla::Mutex;
+  using Thread = mozilla::EventTargetCapability<nsISerialEventTarget>;
+
+  ChannelCapability(const char* mutex_name, nsISerialEventTarget* io_thread)
+      : send_mutex_(mutex_name), io_thread_(io_thread) {}
+
+  const Thread& IOThread() const MOZ_RETURN_CAPABILITY(io_thread_) {
+    return io_thread_;
+  }
+  Mutex& SendMutex() MOZ_RETURN_CAPABILITY(send_mutex_) { return send_mutex_; }
+
+  // Note that we're on the IO thread, and thus have shared access to values
+  // guarded by the channel capability for the thread-safety analysis.
+  void NoteOnIOThread() const MOZ_REQUIRES(io_thread_)
+      MOZ_ASSERT_SHARED_CAPABILITY(this) {}
+
+  // Note that we're holding the send mutex, and thus have shared access to
+  // values guarded by the channel capability for the thread-safety analysis.
+  void NoteSendMutex() const MOZ_REQUIRES(send_mutex_)
+      MOZ_ASSERT_SHARED_CAPABILITY(this) {}
+
+  // Note that we're holding the send mutex while on the IO thread, and thus
+  // have exclusive access to values guarded by the channel capability for the
+  // thread-safety analysis.
+  void NoteExclusiveAccess() const MOZ_REQUIRES(io_thread_, send_mutex_)
+      MOZ_ASSERT_CAPABILITY(this) {}
+
+ private:
+  mozilla::Mutex send_mutex_;
+  mozilla::EventTargetCapability<nsISerialEventTarget> io_thread_;
+};
+
+}  // namespace IPC
+
+#endif  // CHROME_COMMON_IPC_CHANNEL_CAPABILITY_H_