QtLottie: Add support for null layer.

Telegram/ThirdParty/qtlottie

@@ -1 +1 @@
-Subproject commit c9792720e6347afb22c0436274f447c0f958dc02
+Subproject commit 270cd6f31b9c67bdf2ff7cd961df8e5bb86e137c

Telegram/ThirdParty/qtlottie_helper/QtBodymovin/private/bmnulllayer_p.h

@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the lottie-qt module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef BMNULLLAYER_P_H
+#define BMNULLLAYER_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtBodymovin/private/bmlayer_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QJsonObject;
+
+class LottieRenderer;
+class BMShape;
+class BMTrimPath;
+class BMBasicTransform;
+
+class BODYMOVIN_EXPORT BMNullLayer : public BMLayer
+{
+public:
+	BMNullLayer() = default;
+    explicit BMNullLayer(const BMNullLayer &other);
+	BMNullLayer(const QJsonObject &definition);
+    ~BMNullLayer() override;
+
+    BMBase *clone() const override;
+
+    void updateProperties(int frame) override;
+    void render(LottieRenderer &render) const override;
+
+};
+
+QT_END_NAMESPACE
+
+#endif // BMNULLLAYER_P_H

Telegram/gyp/lib_lottie.gyp

@@ -60,11 +60,13 @@
       '<(submodules_loc)/crl/src',
     ],
     'sources': [
+      # interface for tdesktop
       '<(src_loc)/lottie/lottie_animation.cpp',
       '<(src_loc)/lottie/lottie_animation.h',
       '<(src_loc)/lottie/lottie_frame_renderer.cpp',
       '<(src_loc)/lottie/lottie_frame_renderer.h',
 
+      # taken from qtlottie/src/bodymovin/bodymovin.pro
       '<(lottie_loc)/bodymovin/bmbase.cpp',
       '<(lottie_loc)/bodymovin/bmlayer.cpp',
       '<(lottie_loc)/bodymovin/bmshape.cpp',
@@ -115,9 +117,15 @@
       '<(lottie_loc)/bodymovin/bmpathtrimmer_p.h',
       '<(lottie_loc)/bodymovin/bmglobal.h',
 
+      # taken from qtlottie/src/imports/imports.pro
       '<(lottie_loc)/imports/rasterrenderer/lottierasterrenderer.cpp',
 
       '<(lottie_loc)/imports/rasterrenderer/lottierasterrenderer.h',
+
+      # added to qtlottie/src/bodymovin/bodymovin.pro
+      '<(lottie_loc)/bodymovin/bmnulllayer.cpp',
+
+      '<(lottie_loc)/bodymovin/bmnulllayer_p.h',
     ],
     'conditions': [[ 'build_macold', {
       'xcode_settings': {