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

chrome/installer/linux/BUILD.gn

 # 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")
 import("//build/config/features.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/util/process_version.gni")
 import("//build/util/version.gni")
 import("//chrome/process_version_rc_template.gni")  # For branding_file_path.
@@ skipping 173 matching lines @@
   if (enable_nacl) {
     public_deps += [
       "//components/nacl/loader:nacl_helper",
 
       # These are data_deps of nacl_helper, but that is not enough,
       # as explained above.
       "//native_client/src/trusted/service_runtime/linux:bootstrap",
       "//ppapi/native_client:irt",
     ]
   }
   if (current_cpu == "x86" || current_cpu == "x64") {

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

Maybe we should remove this since it does build and it'd be better to have less
conditionals. WDYT?

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

+1

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

I agree, but I'd like to keep this CL minimal to address the specific build
failure.

     public_deps += [
       "//third_party/widevine/cdm:widevinecdm",
       "//third_party/widevine/cdm:widevinecdmadapter",
     ]
   }
   if (!is_chromeos) {
     public_deps += [ ":rpm_packaging_files" ]
   }
 }
 
@@ skipping 26 matching lines @@
   ]
 
   if (current_cpu == "x86") {
     packaging_files_binaries += [ "$root_out_dir/nacl_irt_x86_32.nexe" ]
   } else if (current_cpu == "x64") {
     packaging_files_binaries += [ "$root_out_dir/nacl_irt_x86_64.nexe" ]
   } else if (current_cpu == "arm") {
     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",
     ]
   }
 
   if (is_asan) {
     packaging_files_binaries += [ "$root_out_dir/lib/libc++.so" ]
   }
 
   deb_target_name = "${target_name}_deb"
   action(deb_target_name) {
@@ skipping 99 matching lines @@
 # Other packages that we support that aren't included in the default "linux"
 # target.
 linux_package("trunk") {
   channel = "trunk"
 }
 if (is_asan) {
   linux_package("asan") {
     channel = "asan"
   }
 }