Migrate content/common/gpu/media code to media/gpu

media/gpu/args.gni

Index: media/gpu/args.gni
diff --git a/mojo/public/mojo_constants.gni b/media/gpu/args.gni
similarity index 45%
copy from mojo/public/mojo_constants.gni
copy to media/gpu/args.gni
index 3165a8dc9e2b7d223b1b3e2e9fe25ac30bd1c390..c1511d98ed4ef7bdc033e935e034fa109eb52735 100644
--- a/mojo/public/mojo_constants.gni
+++ b/media/gpu/args.gni
@@ -3,6 +3,10 @@
 # found in the LICENSE file.
 
 declare_args() {
-  # Mojo application directories are created within this subdirectory.
-  mojo_application_subdir = "Mojo Applications"
+  # Indicates if V4L plugin is used.
+  use_v4lplugin = false
+
+  # Indicates if Video4Linux2 codec is used. This is used for all CrOS
+  # platforms which have v4l2 hardware encoder / decoder.
+  use_v4l2_codec = false
 }