Add calls log box.

PeerListBox can have many rows with the same PeerData.
PeerListBox::Row can have arbitrary action on the right side.

Telegram/SourceFiles/calls/calls_box_controller.h

@@ -0,0 +1,51 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop version of Telegram messaging app, see https://telegram.org
+
+Telegram Desktop is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+It is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+In addition, as a special exception, the copyright holders give permission
+to link the code of portions of this program with the OpenSSL library.
+
+Full license: https://github.com/telegramdesktop/tdesktop/blob/master/LICENSE
+Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
+*/
+#pragma once
+
+#include "boxes/peer_list_box.h"
+
+namespace Calls {
+
+class BoxController : public PeerListBox::Controller, private base::Subscriber, private MTP::Sender {
+public:
+	void prepare() override;
+	void rowClicked(PeerListBox::Row *row) override;
+	void rowActionClicked(PeerListBox::Row *row) override;
+	void preloadRows() override;
+
+private:
+	void receivedCalls(const QVector<MTPMessage> &result);
+	void refreshAbout();
+
+	class Row;
+	Row *rowForItem(HistoryItem *item);
+
+	bool appendRow(HistoryItem *item);
+	bool prependRow(HistoryItem *item);
+	std::unique_ptr<PeerListBox::Row> createRow(HistoryItem *item) const;
+
+	MsgId _offsetId = 0;
+	mtpRequestId _loadRequestId = 0;
+	bool _allLoaded = false;
+
+};
+
+} // namespace Calls