[chrome.displaySource] further implementation of call completion callbacks

The API implementation determines when and with which
arguments the 'startSession'/'terminateSession' completion
callbacks are invoked.

The 'exceeded_session_limit_error' session error type is
eliminated and substituted with 'startSession' completion
callback call (which is more natural since this problem is
detected before a new session is started).

JS bindings code is simplified.

BUG=242107

Review URL: https://codereview.chromium.org/1730583002

Cr-Commit-Position: refs/heads/master@{#377864}

4 files changed, 101 insertions, 64 deletions

diff --git a/extensions/renderer/api/display_source/display_source_session.cc b/extensions/renderer/api/display_source/display_source_session.cc
index df83007..20b1442 100644
--- a/extensions/renderer/api/display_source/display_source_session.cc
+++ b/extensions/renderer/api/display_source/display_source_session.cc
@@ -22,15 +22,12 @@ DisplaySourceSession::DisplaySourceSession()
 
 DisplaySourceSession::~DisplaySourceSession() = default;
 
-void DisplaySourceSession::SetCallbacks(
-    const SinkIdCallback& started_callback,
-    const SinkIdCallback& terminated_callback,
+void DisplaySourceSession::SetNotificationCallbacks(
+    const base::Closure& terminated_callback,
     const ErrorCallback& error_callback) {
-  DCHECK(started_callback_.is_null());
   DCHECK(terminated_callback_.is_null());
   DCHECK(error_callback_.is_null());
 
-  started_callback_ = started_callback;
   terminated_callback_ = terminated_callback;
   error_callback_ = error_callback;
 }
diff --git a/extensions/renderer/api/display_source/display_source_session.h b/extensions/renderer/api/display_source/display_source_session.h
index 2c4053c..548958e 100644
--- a/extensions/renderer/api/display_source/display_source_session.h
+++ b/extensions/renderer/api/display_source/display_source_session.h
@@ -23,10 +23,10 @@ using DisplaySourceErrorType = api::display_source::ErrorType;
 // This class represents a generic display source session interface.
 class DisplaySourceSession {
  public:
-  using SinkIdCallback = base::Callback<void(int sink_id)>;
+  using CompletionCallback =
+      base::Callback<void(bool success, const std::string& error_description)>;
   using ErrorCallback =
-      base::Callback<void(int sink_id,
-                          DisplaySourceErrorType error_type,
+      base::Callback<void(DisplaySourceErrorType error_type,
                           const std::string& error_description)>;
 
   // State flow is ether:
@@ -47,36 +47,43 @@ class DisplaySourceSession {
   // Starts the session.
   // The session state should be set to 'Establishing' immediately after this
   // method is called.
-  virtual void Start() = 0;
+  // |callback| : Called with 'success' flag set to 'true' if the session is
+  //              successfully started (state should be set to 'Established')
+  //
+  //              Called with 'success' flag set to 'false' if the session
+  //              has failed to start (state should be set back to 'Idle').
+  //              The 'error_description' argument contains description of
+  //              an error that had caused the call falure.
+  virtual void Start(const CompletionCallback& callback) = 0;
 
   // Terminates the session.
   // The session state should be set to 'Terminating' immediately after this
   // method is called.
-  virtual void Terminate() = 0;
+  // |callback| : Called with 'success' flag set to 'true' if the session is
+  //              successfully terminated (state should be set to 'Idle')
+  //
+  //              Called with 'success' flag set to 'false' if the session
+  //              could not terminate (state should not be modified).
+  //              The 'error_description' argument contains description of
+  //              an error that had caused the call falure.
+  virtual void Terminate(const CompletionCallback& callback) = 0;
 
   State state() const { return state_; }
 
   // Sets the callbacks invoked to inform about the session's state changes.
   // It is required to set the callbacks before the session is started.
-  // |started_callback| : Called when the session was actually started (state
-  //                      should be set to 'Established')
-  // |terminated_callback| : Called when the session was actually started (state
+  // |terminated_callback| : Called when session was terminated (state
   //                         should be set to 'Idle')
   // |error_callback| : Called if a fatal error has occured and the session
-  //                    either cannot be started (if was invoked in
-  //                    'Establishing' state) or will be terminated soon for
-  //                    emergency reasons (if was invoked in 'Established'
-  //                    state).
-  void SetCallbacks(const SinkIdCallback& started_callback,
-                    const SinkIdCallback& terminated_callback,
-                    const ErrorCallback& error_callback);
+  //                    will be terminated soon for emergency reasons.
+  void SetNotificationCallbacks(const base::Closure& terminated_callback,
+                                const ErrorCallback& error_callback);
 
  protected:
   DisplaySourceSession();
 
   State state_;
-  SinkIdCallback started_callback_;
-  SinkIdCallback terminated_callback_;
+  base::Closure terminated_callback_;
   ErrorCallback error_callback_;
 
  private:
diff --git a/extensions/renderer/api/display_source/wifi_display/wifi_display_session.cc b/extensions/renderer/api/display_source/wifi_display/wifi_display_session.cc
index f6d1104..78fd285 100644
--- a/extensions/renderer/api/display_source/wifi_display/wifi_display_session.cc
+++ b/extensions/renderer/api/display_source/wifi_display/wifi_display_session.cc
@@ -38,70 +38,93 @@ WiFiDisplaySession::WiFiDisplaySession(
 WiFiDisplaySession::~WiFiDisplaySession() {
 }
 
-void WiFiDisplaySession::Start() {
-  DCHECK(state_ == DisplaySourceSession::Idle);
+void WiFiDisplaySession::Start(const CompletionCallback& callback) {
+  DCHECK_EQ(DisplaySourceSession::Idle, state_);
+  DCHECK(!terminated_callback_.is_null())
+      << "Should be set with 'SetNotificationCallbacks'";
+  DCHECK(!error_callback_.is_null())
+      << "Should be set with 'SetNotificationCallbacks'";
+
   service_->Connect(params_.sink_id, params_.auth_method, params_.auth_data);
   state_ = DisplaySourceSession::Establishing;
-  if (!started_callback_.is_null())
-    started_callback_.Run(params_.sink_id);
+  start_completion_callback_ = callback;
 }
 
-void WiFiDisplaySession::Terminate() {
-  DCHECK(state_ != DisplaySourceSession::Idle);
-  switch (state_) {
-  case DisplaySourceSession::Idle:
-  case DisplaySourceSession::Terminating:
-    // Nothing to do.
-    return;
-  case DisplaySourceSession::Establishing:
-  case DisplaySourceSession::Established:
-    service_->Disconnect();
-    state_ = DisplaySourceSession::Terminating;
-    break;
-  default:
-    NOTREACHED();
-  }
+void WiFiDisplaySession::Terminate(const CompletionCallback& callback) {
+  DCHECK_EQ(DisplaySourceSession::Established, state_);
+  service_->Disconnect();
+  state_ = DisplaySourceSession::Terminating;
+  teminate_completion_callback_ = callback;
 }
 
-void WiFiDisplaySession::OnEstablished(const mojo::String& ip_address) {
-  DCHECK(state_ != DisplaySourceSession::Established);
+void WiFiDisplaySession::OnConnected(const mojo::String& ip_address) {
+  DCHECK_EQ(DisplaySourceSession::Established, state_);
   ip_address_ = ip_address;
-  state_ = DisplaySourceSession::Established;
+  // TODO(Mikhail): Start Wi-Fi Display session control message exchange.
+}
+
+void WiFiDisplaySession::OnConnectRequestHandled(bool success,
+                                                 const mojo::String& error) {
+  DCHECK_EQ(DisplaySourceSession::Establishing, state_);
+  state_ =
+      success ? DisplaySourceSession::Established : DisplaySourceSession::Idle;
+  RunStartCallback(success, error);
 }
 
 void WiFiDisplaySession::OnTerminated() {
-  DCHECK(state_ != DisplaySourceSession::Idle);
+  DCHECK_NE(DisplaySourceSession::Idle, state_);
   state_ = DisplaySourceSession::Idle;
-  if (!terminated_callback_.is_null())
-    terminated_callback_.Run(params_.sink_id);
+  terminated_callback_.Run();
+}
+
+void WiFiDisplaySession::OnDisconnectRequestHandled(bool success,
+                                                    const mojo::String& error) {
+  RunTerminateCallback(success, error);
 }
 
 void WiFiDisplaySession::OnError(int32_t type,
                                  const mojo::String& description) {
   DCHECK(type > api::display_source::ERROR_TYPE_NONE
          && type <= api::display_source::ERROR_TYPE_LAST);
-  if (!error_callback_.is_null())
-    error_callback_.Run(params_.sink_id, static_cast<ErrorType>(type),
-                        description);
+  DCHECK_EQ(DisplaySourceSession::Established, state_);
+  error_callback_.Run(static_cast<ErrorType>(type), description);
 }
 
 void WiFiDisplaySession::OnMessage(const mojo::String& data) {
-  DCHECK(state_ == DisplaySourceSession::Established);
+  DCHECK_EQ(DisplaySourceSession::Established, state_);
 }
 
 void WiFiDisplaySession::OnConnectionError() {
-  if (!error_callback_.is_null()) {
-    error_callback_.Run(params_.sink_id,
-                        api::display_source::ERROR_TYPE_UNKNOWN_ERROR,
-                        kErrorInternal);
+  // We must explicitly notify the session termination as it will never
+  // arrive from browser process (IPC is broken).
+  switch (state_) {
+    case DisplaySourceSession::Idle:
+    case DisplaySourceSession::Establishing:
+      RunStartCallback(false, kErrorInternal);
+      break;
+    case DisplaySourceSession::Terminating:
+    case DisplaySourceSession::Established:
+      error_callback_.Run(api::display_source::ERROR_TYPE_UNKNOWN_ERROR,
+                          kErrorInternal);
+      state_ = DisplaySourceSession::Idle;
+      terminated_callback_.Run();
+      break;
+    default:
+      NOTREACHED();
   }
+}
 
-  if (state_ != DisplaySourceSession::Idle) {
-    // We must explicitly notify the session termination as it will never
-    // arrive from browser process (IPC is broken).
-    if (!terminated_callback_.is_null())
-      terminated_callback_.Run(params_.sink_id);
-  }
+void WiFiDisplaySession::RunStartCallback(bool success,
+                                          const std::string& error_message) {
+  if (!start_completion_callback_.is_null())
+    start_completion_callback_.Run(success, error_message);
+}
+
+void WiFiDisplaySession::RunTerminateCallback(
+    bool success,
+    const std::string& error_message) {
+  if (!teminate_completion_callback_.is_null())
+    teminate_completion_callback_.Run(success, error_message);
 }
 
 }  // namespace extensions
diff --git a/extensions/renderer/api/display_source/wifi_display/wifi_display_session.h b/extensions/renderer/api/display_source/wifi_display/wifi_display_session.h
index 5d10308..7eeb987 100644
--- a/extensions/renderer/api/display_source/wifi_display/wifi_display_session.h
+++ b/extensions/renderer/api/display_source/wifi_display/wifi_display_session.h
@@ -21,24 +21,34 @@ class WiFiDisplaySession: public DisplaySourceSession,
   ~WiFiDisplaySession() override;
 
  private:
+  using DisplaySourceSession::CompletionCallback;
   // DisplaySourceSession overrides.
-  void Start() override;
-  void Terminate() override;
+  void Start(const CompletionCallback& callback) override;
+  void Terminate(const CompletionCallback& callback) override;
 
   // WiFiDisplaySessionServiceClient overrides.
-  void OnEstablished(const mojo::String& ip_address) override;
+  void OnConnected(const mojo::String& ip_address) override;
+  void OnConnectRequestHandled(bool success,
+                               const mojo::String& error) override;
   void OnTerminated() override;
+  void OnDisconnectRequestHandled(bool success,
+                                  const mojo::String& error) override;
   void OnError(int32_t type, const mojo::String& description) override;
   void OnMessage(const mojo::String& data) override;
 
   // A connection error handler for the mojo objects used in this class.
   void OnConnectionError();
 
+  void RunStartCallback(bool success, const std::string& error = "");
+  void RunTerminateCallback(bool success, const std::string& error = "");
+
  private:
   WiFiDisplaySessionServicePtr service_;
   mojo::Binding<WiFiDisplaySessionServiceClient> binding_;
   std::string ip_address_;
   DisplaySourceSessionParams params_;
+  CompletionCallback start_completion_callback_;
+  CompletionCallback teminate_completion_callback_;
   base::WeakPtrFactory<WiFiDisplaySession> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WiFiDisplaySession);