Revert of [cast_channel] Move cast_channel related files from //extensions to //components

extensions/browser/api/cast_channel/keep_alive_delegate.h

+// Copyright 2015 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 EXTENSIONS_BROWSER_API_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_
+#define EXTENSIONS_BROWSER_API_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_
+
+#include "base/macros.h"
+#include "base/threading/thread_checker.h"
+#include "base/timer/timer.h"
+#include "extensions/browser/api/cast_channel/cast_transport.h"
+#include "extensions/common/api/cast_channel/cast_channel.pb.h"
+
+namespace extensions {
+namespace api {
+namespace cast_channel {
+
+class CastSocket;
+class Logger;
+
+// Decorator delegate which provides keep-alive functionality.
+// Keep-alive messages are handled by this object; all other messages and
+// errors are passed to |inner_delegate_|.
+class KeepAliveDelegate : public CastTransport::Delegate {
+ public:
+  // |socket|: The socket to be kept alive.
+  // |logger|: The logging object which collects protocol events and error
+  //           details.
+  // |inner_delegate|: The delegate which processes all non-keep-alive
+  //                   messages. This object assumes ownership of
+  //                   |inner_delegate|.
+  // |ping_interval|: The amount of idle time to wait before sending a PING to
+  //                  the remote end.
+  // |liveness_timeout|: The amount of idle time to wait before terminating the
+  //                     connection.
+  KeepAliveDelegate(CastSocket* socket,
+                    scoped_refptr<Logger> logger,
+                    std::unique_ptr<CastTransport::Delegate> inner_delegate,
+                    base::TimeDelta ping_interval,
+                    base::TimeDelta liveness_timeout);
+
+  ~KeepAliveDelegate() override;
+
+  // Creates a keep-alive message (e.g. PING or PONG).
+  static CastMessage CreateKeepAliveMessage(const char* message_type);
+
+  void SetTimersForTest(std::unique_ptr<base::Timer> injected_ping_timer,
+                        std::unique_ptr<base::Timer> injected_liveness_timer);
+
+  // CastTransport::Delegate implementation.
+  void Start() override;
+  void OnError(ChannelError error_state) override;
+  void OnMessage(const CastMessage& message) override;
+
+  static const char kHeartbeatPingType[];
+  static const char kHeartbeatPongType[];
+
+ private:
+  // Restarts the ping/liveness timeout timers. Called when a message
+  // is received from the remote end.
+  void ResetTimers();
+
+  // Sends a formatted PING or PONG message to the remote side.
+  void SendKeepAliveMessage(const CastMessage& message,
+                            const char* message_type);
+
+  // Callback for SendKeepAliveMessage.
+  void SendKeepAliveMessageComplete(const char* message_type, int rv);
+
+  // Called when the liveness timer expires, indicating that the remote
+  // end has not responded within the |liveness_timeout_| interval.
+  void LivenessTimeout();
+
+  // Stops the ping and liveness timers if they are started.
+  // To be called after an error.
+  void Stop();
+
+  // Indicates that Start() was called.
+  bool started_;
+
+  // Socket that is managed by the keep-alive object.
+  CastSocket* socket_;
+
+  // Logging object.
+  scoped_refptr<Logger> logger_;
+
+  // Delegate object which receives all non-keep alive messages.
+  std::unique_ptr<CastTransport::Delegate> inner_delegate_;
+
+  // Amount of idle time to wait before disconnecting.
+  base::TimeDelta liveness_timeout_;
+
+  // Amount of idle time to wait before pinging the receiver.
+  base::TimeDelta ping_interval_;
+
+  // Fired when |ping_interval_| is exceeded or when triggered by test code.
+  std::unique_ptr<base::Timer> ping_timer_;
+
+  // Fired when |liveness_timer_| is exceeded.
+  std::unique_ptr<base::Timer> liveness_timer_;
+
+  // The PING message to send over the wire.
+  CastMessage ping_message_;
+
+  // The PONG message to send over the wire.
+  CastMessage pong_message_;
+
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(KeepAliveDelegate);
+};
+
+}  // namespace cast_channel
+}  // namespace api
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_