Add -pie to chrome on Linux in GN.

chrome/BUILD.gn

 # Copyright 2014 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/locales.gni")
 import("//build/config/ui.gni")
 import("//chrome/chrome_repack_locales.gni")
 import("//chrome/version.gni")
@@ skipping 98 matching lines @@
         "//base/allocator",
 
         # Needed to use the master_preferences functions
         "//chrome/installer/util",
         "//content/public/app:both",
       ]
 
       # Needed for chrome_main.cc initialization of libraries.
       configs += [ "//build/config/linux:pangocairo" ]
 
-      # TODO(GYP) ['profiling==0 and linux_disable_pie==0', {
-      #   'ldflags': [
-      #      '-pie',
-      #   ],
-      #}],
+      # GYP has this in a 'profiling==0 and linux_disable_pie==0' condition.
+      # but GN doesn't have either of these flags.
+      ldflags = [ "-pie" ]
 
       if (use_x11) {
         configs += [
           "//build/config/linux:x11",
           "//build/config/linux:xext",
         ]
       }
     }
 
     if (is_mac) {
@@ skipping 646 matching lines @@
 
     args = [
       rebase_path(infile, root_build_dir),
       rebase_path(outfile, root_build_dir),
       "-e s/@@NAME@@/$name/",
       "-e s/@@FILENAME@@/$filename/",
       "-e s/@@CONFDIR@@/$confdir/",
     ]
   }
 }