Update build requirements

Author: magreenblatt

CMakeLists.txt

@@ -10,9 +10,9 @@
 #
 # CMake-generated project formats that have been tested with JCEF include:
 #
-# Linux:      Ninja, Unix Makefiles
-# MacOS:      Ninja, Xcode 8+ (x86_64) or Xcode 12.2+ (ARM64)
-# Windows:    Ninja, Visual Studio 2015+
+# Linux:      Ninja, GCC 7.5.0+, Unix Makefiles
+# MacOS:      Ninja, Xcode 12.2 to 13.0
+# Windows:    Ninja, Visual Studio 2019+
 #
 # Ninja is a cross-platform open-source tool for running fast builds using
 # pre-installed platform toolchains (GNU, clang, Xcode or MSVC). It can be
@@ -23,24 +23,27 @@
 #
 # The below requirements must be met to build JCEF.
 #
-# - CMake version 2.8.12.1 or newer.
+# - CMake version 3.19 or newer.
 #
 # - Linux requirements:
-#   Currently supported distributions include Debian Wheezy, Ubuntu Precise, and
-#   related. Ubuntu 18.04 64-bit is recommended. Newer versions will likely also
-#   work but may not have been tested.
+#   Currently supported distributions include Debian 10 (Buster), Ubuntu 18
+#   (Bionic Beaver), and related. Ubuntu 18.04 64-bit with GCC 7.5.0+ is
+#   recommended. Newer versions will likely also work but may not have been
+#   tested.
 #   Required packages include:
 #     build-essential
+#     libgtk3.0-dev     (required by the cefclient target only)
 #
 # - MacOS requirements:
-#   Xcode 8 or newer building on MacOS 10.11 (El Capitan) or newer for x86_64.
-#   Xcode 12.2 or newer building on MacOS 10.15.4 (Catalina) or newer for ARM64.
-#   Only 64-bit builds are supported. The Xcode command-line tools must also be
-#   installed.
+#   Xcode 12.2 to 13.0 building on MacOS 10.15.4 (Catalina) or newer. Only
+#   64-bit builds are supported. The Xcode command-line tools must also be
+#   installed. Newer Xcode versions may not have been been tested and are not
+#   recommended.
 #
 # - Windows requirements:
-#   Visual Studio 2015 Update 2 or newer building on Windows 7 or newer. Visual
-#   Studio 2019 and Windows 10 64-bit are recommended.
+#   Visual Studio 2019 or newer building on Windows 7 or newer. Windows 10
+#   64-bit is recommended. Newer versions will likely also work but may not have
+#   been tested.
 #
 # BUILD EXAMPLES
 #
@@ -108,7 +111,8 @@
 # Shared configuration.
 #
 
-cmake_minimum_required(VERSION 2.8.12.1)
+# For VS2019 and Xcode 12+ support.
+cmake_minimum_required(VERSION 3.19)
 
 # Only generate Debug and Release configuration types.
 set(CMAKE_CONFIGURATION_TYPES Debug Release)