GN files, initial check in

First version of Chromium build files for SwiftShader.
Works for Linux only at this point.
Other platforms are there, but untested at the moment.

Change-Id: I8f389db9937feda74c7009cf7a22938dab9e69d5
Reviewed-on: https://swiftshader-review.googlesource.com/5520
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
diff --git a/src/OpenGL/libEGL/BUILD.gn b/src/OpenGL/libEGL/BUILD.gn
new file mode 100644
index 0000000..ddd4b94
--- /dev/null
+++ b/src/OpenGL/libEGL/BUILD.gn
@@ -0,0 +1,69 @@
+# Copyright 2016 The SwiftShader Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Need a separate config to ensure the warnings are added to the end.
+config("swiftshader_libEGL_private_config") {
+  if (is_clang) {
+    cflags = [
+      "-DLOG_TAG=\"swiftshader_libEGL\"",
+      "-DEGLAPI=",
+      "-DEGL_EGLEXT_PROTOTYPES",
+      "-Wno-sign-compare",
+    ]
+
+    if (!is_debug) {
+      cflags += [
+        "-DNDEBUG",
+        "-DANGLE_DISABLE_TRACE",
+      ]
+    }
+  }
+}
+
+shared_library("swiftshader_libEGL") {
+  deps = [
+    "../../Common:swiftshader_common",
+    "../../Reactor:swiftshader_reactor",
+    "../../Renderer:swiftshader_renderer",
+    "../../OpenGL/common:swiftshader_opengl_common",
+    "../../OpenGL/compiler:swiftshader_opengl_compiler",
+    "../../Shader:swiftshader_shader",
+    "../../Main:swiftshader_main",
+    "../../../third_party/LLVM:swiftshader_llvm",
+  ]
+
+  sources = [
+    "Config.cpp",
+    "Display.cpp",
+    "Surface.cpp",
+    "libEGL.cpp",
+    "main.cpp",
+  ]
+
+  if (host_os == "mac") {
+    sources += [
+      "OSXUtils.mm",
+    ]
+  }
+
+  configs += [
+    ":swiftshader_libEGL_private_config",
+  ]
+
+  include_dirs = [
+    "../../../include",
+    "../..",
+    "..",
+  ]
+}
\ No newline at end of file