[chrome.displaySource] Add WiFi Display session class skeleton and mojo service

extensions/renderer/api/display_source/wifi_display/wifi_display_session.cc

+// 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.
+
+#include "extensions/renderer/api/display_source/wifi_display/wifi_display_session.h"
+
+#include "base/logging.h"
+#include "base/timer/timer.h"
+#include "content/public/common/service_registry.h"
+#include "content/public/renderer/render_frame.h"
+
+namespace extensions {
+
+using api::display_source::ErrorType;
+
+WiFiDisplaySession::WiFiDisplaySession(
+    const DisplaySourceSessionParams& params)
+  : binding_(this),
+    params_(params) {
+  CHECK(params_.render_frame);

[Ken Rockot(use gerrit already), 2016/01/05 17:21:37]

In general these CHECKs should probably just be DCHECKs

[Mikhail, 2016/01/11 19:39:41]

Done.

+  params.render_frame->GetServiceRegistry()->ConnectToRemoteService(
+      mojo::GetProxy(&service_));
+  CHECK(service_);
+  WiFiDisplaySessionServiceClientPtr client_ptr;
+  binding_.Bind(GetProxy(&client_ptr));
+  CHECK(client_ptr);
+
+  service_->SetClient(std::move(client_ptr));

[Ken Rockot(use gerrit already), 2016/01/05 17:21:37]

You probably want to set a connection error handler on service_ and binding_ to
detect a broken pipe

[Mikhail, 2016/01/11 19:39:41]

Done.

+}
+
+WiFiDisplaySession::~WiFiDisplaySession() {
+}
+
+void WiFiDisplaySession::Start() {
+  DCHECK(state_ == DisplaySourceSession::Idle);
+  service_->Connect(params_.sink_id, params_.auth_method, params_.auth_data);
+  state_ = DisplaySourceSession::Establishing;
+}
+
+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::OnConnected(
+    int32_t sink_id, const mojo::String& ip_address) {
+  DCHECK(state_ != DisplaySourceSession::Established);
+  if (sink_id == params_.sink_id) {
+    ip_address_ = ip_address;
+    state_ = DisplaySourceSession::Established;
+  }
+
+  if (!started_callback_.is_null())
+    started_callback_.Run(sink_id);
+}
+
+void WiFiDisplaySession::OnDisconnected(int32_t sink_id) {
+  DCHECK(state_ == DisplaySourceSession::Established);
+  if (sink_id == params_.sink_id) {
+    state_ = DisplaySourceSession::Idle;
+  }
+
+  if (!terminated_callback_.is_null())
+    terminated_callback_.Run(sink_id);
+}
+
+void WiFiDisplaySession::OnError(
+    int32_t sink_id, 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(sink_id, static_cast<ErrorType>(type), description);
+}
+
+void WiFiDisplaySession::OnMessage(const mojo::String& data) {
+  DCHECK(state_ == DisplaySourceSession::Established);
+}
+
+}  // namespace extensions