GN: Avoid nontrivial shell commands in gcc_toolchain tool("link")

remoting/webapp/build_template.gni

 # 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.
 
 # Keep in sync with 'remoting_webapp' target in remoting/remoting_client.gypi.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/features.gni")
 import("//build/util/version.gni")
 import("//remoting/remoting_locales.gni")
@@ skipping 179 matching lines @@
     dr_generated_html_files = [
       background_html_output,
       message_window_html_output,
       wcs_sandbox_html_output,
       main_html_output,
       public_session_html_output,
       "$target_gen_dir/credits.html",
     ]
 
     if (enable_pnacl) {
-      pexe_dir = get_label_info(
-              "//remoting/client/plugin:remoting_client_plugin_newlib(//build/toolchain/nacl:newlib_pnacl)",
-              "root_out_dir")
+      pnacl_tc = "//build/toolchain/nacl:newlib_pnacl"
+      pexe_label = "//remoting/client/plugin:remoting_client_plugin_newlib"
+      pexe_dir = get_label_info("${pexe_label}($pnacl_tc)", "root_out_dir")
 
       extra_files += [ "$pexe_dir/remoting_client_plugin_newlib.pexe" ]
       if (is_debug) {
         extra_files += [ "$pexe_dir/remoting_client_plugin_newlib.pexe.debug" ]
       }
     }
 
     inputs = [ rebase_path("crd/manifest.json.jinja2", root_build_dir) ] +
              remoting_version_files +
              rebase_path(remoting_webapp_crd_files, root_build_dir) +
              extra_files + dr_generated_html_files
 
     outputs = [
       zip_path,
     ]
 
     deps = [
       ":$locales_listfile",
       ":$background_html",
       ":$message_window_html",
       ":$wcs_sandbox_html",
       ":$public_session_html",
       ":$main_html",
       "//remoting/resources",
       "//remoting/webapp:credits",
     ]
 
     if (enable_pnacl) {
-      deps += [ "//remoting/client/plugin:remoting_client_plugin_newlib(//build/toolchain/nacl:newlib_pnacl)" ]
+      deps += [ "${pexe_label}($pnacl_tc)" ]
+      if (is_debug) {
+        deps += [ "${pexe_label}_debug($pnacl_tc)" ]
+      }
     }
 
     # Create a file that contains a list of all the resource files needed
     # to build the webapp. This is needed to avoid problems on platforms that
     # limit the size of a command line.
     file_list = "$target_gen_dir/${target_name}_files.txt"
     files = []
     files += rebase_path(dr_generated_html_files, root_build_dir)
     files += rebase_path(remoting_webapp_crd_files, root_build_dir)
     files += rebase_path(extra_files, root_build_dir)
@@ skipping 296 matching lines @@
     args += [
       "--files_listfile",
       rebase_path(file_list, root_build_dir),
     ]
     args += [
       "--locales_listfile",
       rebase_path(locales_listfile_output, root_build_dir),
     ]
   }
 }