[PresentationAPI] Implementing start/joinSession from WebPresentationClient to PresentationService.

content/renderer/presentation/presentation_session_client.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 "content/renderer/presentation/presentation_session_client.h"
+
+#include "base/logging.h"
+#include "content/renderer/presentation/presentation_session_dispatcher.h"
+#include "third_party/WebKit/public/platform/WebString.h"
+
+namespace content {
+
+PresentationSessionClient::PresentationSessionClient(
+    PresentationSessionDispatcher* dispatcher)
+    : url_(blink::WebString::fromUTF8(dispatcher->GetUrl())),
+      id_(blink::WebString::fromUTF8(dispatcher->GetId())) {
+}
+
+PresentationSessionClient::~PresentationSessionClient() {
+}
+
+blink::WebString PresentationSessionClient::getUrl() {
+    return url_;
+}
+
+blink::WebString PresentationSessionClient::getId() {
+    return id_;
+}
+
+}  // namespace content