Fix gn installer/linux/BUILD.gn with target_arch=arm

chrome/installer/linux/BUILD.gn

Index: chrome/installer/linux/BUILD.gn
diff --git a/chrome/installer/linux/BUILD.gn b/chrome/installer/linux/BUILD.gn
index fcc2d753fad79d4979df45495f45ce918ad4eabd..c6c9eba73216de64899a771ad37aa5a01b30c849 100644
--- a/chrome/installer/linux/BUILD.gn
+++ b/chrome/installer/linux/BUILD.gn
@@ -238,7 +238,7 @@ template("linux_package") {
     packaging_files_binaries += [ "$root_out_dir/nacl_irt_arm.nexe" ]
   }
 
-  if (is_chrome_branded) {
+  if (is_chrome_branded && (current_cpu == "x86" || current_cpu == "x64")) {

[ddorwin, 2016/10/07 22:37:52]

You might explain this in a comment. For example, the Widevine BUILD.gn file
only produces binaries for these architectures.

[Sam Clegg, 2016/10/07 22:51:48]

Done.

     packaging_files_binaries += [
       "$root_out_dir/$widevine_cdm_path/libwidevinecdmadapter.so",

[ddorwin, 2016/10/07 22:37:52]

I wonder if this should be the output of the build dependencies rather than
explicitly specified here. There is some issue with moving/copying the files,
though. +xhwang.

[xhwang, 2016/10/07 22:51:27]

I was following other examples in this file and I am not sure how we can get the
output files by depending on the cdm targets.

[Sam Clegg, 2016/10/07 22:51:48]

Sounds like a good idea, but something for another CL perhaps?

       "$root_out_dir/$widevine_cdm_path/libwidevinecdm.so",