[Presentation API] Add layout test for connection.close() and fix test failures

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

 // 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.
 
 #ifndef WebPresentationConnection_h
 #define WebPresentationConnection_h
 
 #include "public/platform/WebCommon.h"
 
 #include <memory>
 
 namespace blink {
 
+enum class WebPresentationConnectionCloseReason;
 enum class WebPresentationConnectionState;
 class WebPresentationConnectionProxy;
 class WebString;
 
 // Implemented by the embedder for a PresentationConnection.
 class WebPresentationConnection {
  public:
   virtual ~WebPresentationConnection() = default;
 
   // Takes ownership of |proxy| and stores it in connection object. Should be
   // called only once.
   virtual void bindProxy(std::unique_ptr<WebPresentationConnectionProxy>) = 0;
 
   // Notifies the presentation about new message.
   virtual void didReceiveTextMessage(const WebString& message) = 0;
   virtual void didReceiveBinaryMessage(const uint8_t* data, size_t length) = 0;
 
   // Notifies the connection about its state change.
   virtual void didChangeState(WebPresentationConnectionState) = 0;
+
+  // Notifies the connection about its state change to 'closed'.
+  virtual void didClose(WebPresentationConnectionCloseReason,

[mark a. foltz, 2017/03/06 18:57:55]

Can you remove the message argument since it's always empty?

My thought is to have an API with a did() method for each of the close reasons,
especially since there is no message for the "Closed" or "WentAway" reasons.

e.g.

didError(message) => Error
didClose() => Closed 
didGoAway() => WentAway

(Not asking for this change here though.)

[zhaobin, 2017/03/06 19:52:23]

Done.

+                        const WebString& message) = 0;
 };
 
 }  // namespace blink
 
 #endif  // WebPresentationConnection_h