Support generic synchronization against an IPC::Channel

ipc/ipc_message_pipe_reader.h

 // Copyright 2014 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.
 
 #ifndef IPC_IPC_MESSAGE_PIPE_READER_H_
 #define IPC_IPC_MESSAGE_PIPE_READER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 68 matching lines @@
   bool IsValid() { return sender_; }
 
   // Sends an IPC::Message to the other end of the pipe. Safe to call from any
   // thread.
   bool Send(std::unique_ptr<Message> message);
 
   // Requests an associated interface from the other end of the pipe.
   void GetRemoteInterface(const std::string& name,
                           mojo::ScopedInterfaceEndpointHandle handle);
 
+  // Sends an Event to be signalled ASAP from the other side of the channel.
+  void SendEventToSignal(mojo::common::mojom::EventPtr event);
+
   base::ProcessId GetPeerPid() const { return peer_pid_; }
 
   mojom::Channel* sender() const { return sender_.get(); }
 
  protected:
   void OnPipeClosed();
   void OnPipeError(MojoResult error);
 
  private:
   // mojom::Channel:
   void SetPeerPid(int32_t peer_pid) override;
   void Receive(
       const std::vector<uint8_t>& data,
       base::Optional<std::vector<mojom::SerializedHandlePtr>> handles) override;
   void GetAssociatedInterface(
       const std::string& name,
       mojom::GenericInterfaceAssociatedRequest request) override;
+  void SignalEvent(mojo::common::mojom::EventPtr event) override;
 
   // |delegate_| is null once the message pipe is closed.
   Delegate* delegate_;
   base::ProcessId peer_pid_ = base::kNullProcessId;
   mojom::ChannelAssociatedPtr sender_;
   mojo::AssociatedBinding<mojom::Channel> binding_;
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePipeReader);
 };
 
 }  // namespace internal
 }  // namespace IPC
 
 #endif  // IPC_IPC_MESSAGE_PIPE_READER_H_