media: More cleanup in cdm_paths.*

media/cdm/ppapi/cdm_paths.gni

Index: media/cdm/ppapi/cdm_paths.gni
diff --git a/media/cdm/ppapi/cdm_paths.gni b/media/cdm/ppapi/cdm_paths.gni
index 3d166d004eb9c5cf656b9dbcb1fa7cf3d173d3d2..52f535e621cc39536b90c0645f0e38091711b1bd 100644
--- a/media/cdm/ppapi/cdm_paths.gni
+++ b/media/cdm/ppapi/cdm_paths.gni
@@ -20,17 +20,22 @@ if (is_chromeos) {
 } else if (is_mac) {
   component_os = "mac"
 } else {
-  component_os = "$target_os"
+  component_os = "unsupported_platform"
+}
+
+if (target_cpu == "x86" || target_cpu == "x64" || target_cpu == "arm") {
+  component_arch = "$target_cpu"
+} else {
+  component_arch = "unsupported_arch"
 }
 
 # Only enable platform specific path for Win and Mac, where CDMs are Chrome
 # components.
 # TODO(xhwang): Improve how we enable platform specific path. See
 # http://crbug.com/468584
-if (is_win || is_mac) {
-  # Architecture name for components is the same as "<(target_cpu)".
+if ((is_win || is_mac) && (target_cpu == "x86" || target_cpu == "x64")) {
   _platform_specific_path =
-      "_platform_specific/$component_os" + "_" + "$target_cpu"
+      "_platform_specific/$component_os" + "_" + "$component_arch"
 
   # Path of Clear Key and Widevine CDMs relative to the output dir.
   clearkey_cdm_path = "ClearKeyCdm/$_platform_specific_path"