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

Add layout test.

1-UA connection.close() hits NOTREACHED() in PresentationConnection::didChangeState(). Use PresentationConnection::didClose() instead.

BUG=697719

Review-Url: https://codereview.chromium.org/2730123003
Cr-Commit-Position: refs/heads/master@{#455225}
void PresentationConnection::send(Blob* data, ExceptionState& exceptionState) {
  ASSERT(data);
  if (!canSendMessage(exceptionState))
    return;

  m_messages.append(new Message(data->blobDataHandle()));
  handleMessageQueue();
}

void PresentationConnection::send(Blob* data, ExceptionState& exceptionState) {
  ASSERT(data);
  if (!canSendMessage(exceptionState))
    return;

  m_messages.append(new Message(data->blobDataHandle()));
  handleMessageQueue();
}
