[Presentation API] (alternative) 1-UA: send message between controller and receiver page

third_party/WebKit/public/platform/modules/presentation/WebPresentationConnectionProxy.h

+// Copyright 2016 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 WebPresentationConnectionProxy_h
+#define WebPresentationConnectionProxy_h
+
+namespace blink {
+
+class WebPresentationConnection;
+
+// The implementation the embedder has to provide for the Presentation API to
+// work.

[mark a. foltz, 2016/10/21 00:53:03]

Can you describe what functions specifically have to be implemented by this
class?

For example,

"Used to send and receive messages from a PresentationConnection hosted in a
different frame."

[zhaobin, 2016/10/22 02:44:14]

Done.

+class WebPresentationConnectionProxy {
+ public:
+  virtual ~WebPresentationConnectionProxy() {}
+
+  virtual void SetSourceConnection(blink::WebPresentationConnection*) = 0;
+
+  virtual void SendString(const blink::WebString& message) = 0;
+
+  virtual void SendArrayBuffer(const uint8_t* data, size_t length) = 0;
+};
+
+}  // namespace blink
+
+#endif  // WebPresentationConnectionProxy_h