Adding third_party/openh264 build files for encoding

third_party/openh264/openh264_args.gni

Index: third_party/openh264/openh264_args.gni
diff --git a/third_party/openh264/openh264_args.gni b/third_party/openh264/openh264_args.gni
new file mode 100644
index 0000000000000000000000000000000000000000..3ef8e9e9507627d193cabf911b45acd825263304
--- /dev/null
+++ b/third_party/openh264/openh264_args.gni
@@ -0,0 +1,14 @@
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/chrome_build.gni")
+
+declare_args() {
+  # Enable this to build OpenH264.
+  # CHECK THE OPENH264 LICENSE BEFORE BUILDING. Chrome builds this by default,
+  # but non-Chrome builds need this to default to false due to license and
+  # patent reasons, see http://www.openh264.org/. In both cases the default
+  # value can be overwritten.
+  use_openh264 = is_chrome_branded
+}