[cast_channel] Make cast_channel related files not depend on "cast_channel.h"

components/cast_channel/cast_channel_enum.cc

+// Copyright 2017 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 "components/cast_channel/cast_channel_enum.h"
+
+#include "base/logging.h"
+
+namespace cast_channel {
+
+#define CAST_CHANNEL_TYPE_TO_STRING(enum) \
+  case enum:                              \
+    return #enum
+
+std::string ReadyStateToString(ReadyState ready_state) {
+  switch (ready_state) {
+    CAST_CHANNEL_TYPE_TO_STRING(ReadyState::NONE);
+    CAST_CHANNEL_TYPE_TO_STRING(ReadyState::CONNECTING);
+    CAST_CHANNEL_TYPE_TO_STRING(ReadyState::OPEN);
+    CAST_CHANNEL_TYPE_TO_STRING(ReadyState::CLOSING);
+    CAST_CHANNEL_TYPE_TO_STRING(ReadyState::CLOSED);
+  }
+  NOTREACHED() << "Unknown ready_state " << ReadyStateToString(ready_state);
+  return "Unknown ready_state";
+}
+
+std::string ChannelErrorToString(ChannelError channel_error) {
+  switch (channel_error) {
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::NONE);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::CHANNEL_NOT_OPEN);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::AUTHENTICATION_ERROR);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::CONNECT_ERROR);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::CAST_SOCKET_ERROR);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::TRANSPORT_ERROR);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::INVALID_MESSAGE);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::INVALID_CHANNEL_ID);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::CONNECT_TIMEOUT);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::PING_TIMEOUT);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelError::UNKNOWN);
+  }
+  NOTREACHED() << "Unknown channel_error "
+               << ChannelErrorToString(channel_error);
+  return "Unknown channel_error";
+}
+
+std::string ChannelAuthTypeToString(ChannelAuthType channel_auth) {
+  switch (channel_auth) {
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelAuthType::NONE);
+    CAST_CHANNEL_TYPE_TO_STRING(ChannelAuthType::SSL_VERIFIED);
+  }
+  NOTREACHED() << "Unknown channel_auth "
+               << ChannelAuthTypeToString(channel_auth);
+  return "Unknown channel_auth";
+}
+
+}  // namespace cast_channel