Use system libsrtp if available

Adds configure check and configures chromium to use system libsrtp if
available.

Change-Id: I134c50e1179bfb6acf01347456f8be26f27bf559
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

src/core/config/desktop_linux.pri

@@ -22,6 +22,7 @@ contains(QT_CONFIG, system-png): GYP_CONFIG += use_system_libpng=1
 contains(QT_CONFIG, system-jpeg): GYP_CONFIG += use_system_libjpeg=1
 config_system_libevent: GYP_CONFIG += use_system_libevent=1
 config_system_libwebp: GYP_CONFIG += use_system_libwebp=1
+config_system_libsrtp: GYP_CONFIG += use_system_libsrtp=1
 config_system_libxslt: GYP_CONFIG += use_system_libxml=1
 config_system_flac: GYP_CONFIG += use_system_flac=1
 config_system_jsoncpp: GYP_CONFIG += use_system_jsoncpp=1

src/core/config/embedded_linux.pri

@@ -55,6 +55,7 @@ contains(QT_CONFIG, system-jpeg): GYP_CONFIG += use_system_libjpeg=1
 !contains(QT_CONFIG, pulseaudio): GYP_CONFIG += use_pulseaudio=0
 config_system_libevent: GYP_CONFIG += use_system_libevent=1
 config_system_libwebp: GYP_CONFIG += use_system_libwebp=1
+config_system_libsrtp: GYP_CONFIG += use_system_libsrtp=1
 config_system_libxslt: GYP_CONFIG += use_system_libxml=1
 config_system_flac: GYP_CONFIG += use_system_flac=1
 config_system_jsoncpp: GYP_CONFIG += use_system_jsoncpp=1

tools/qmake/config.tests/srtp/srtp.cpp

+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <srtp/srtp.h>
+
+int main(int, char **)
+{
+    err_status_t status = srtp_init();
+    return status == err_status_ok;
+}

tools/qmake/config.tests/srtp/srtp.pro

+linux:SOURCES += srtp.cpp
+LIBS += -lsrtp
+CONFIG -= qt

tools/qmake/mkspecs/features/configure.prf

@@ -41,6 +41,8 @@ defineTest(runConfigure) {
         }
         packagesExist("\'vpx >= 1.4\'"): WEBENGINE_CONFIG += config_system_vpx
         else: log("System vpx >= 1.4 not found. Using Chromium's copy.$${EOL}")
+        config_srtp: WEBENGINE_CONFIG += config_system_libsrtp
+        else: log("System libsrtp not found. Using Chromium's copy.$${EOL}")
     }
 
     isEmpty(skipBuildReason): {