Use output_all_resource_defines=false in most grd files.

ios/chrome/today_extension/strings/ios_today_extension_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 This file contains definition of resources that will be translated for each
 locale.  The variables is_win, is_macosx, is_linux, is_ios and is_posix are
 available for making strings OS specific.  Other platform defines such as
 use_titlecase are declared in build/common.gypi.
 
 The strings in this file are specific to iOS, thus is_ios will be true and
 all other OS specific variables will be false.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
-      source_lang_id="en" enc_check="möl">
+      output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
     <output filename="grit/ios_today_extension_strings.h" type="rc_header">
       <emit emit_type="prepend"></emit>
     </output>
     <output filename="ios_today_extension_strings_am.pak" type="data_package" lang="am" />
     <output filename="ios_today_extension_strings_ar.pak" type="data_package" lang="ar" />
     <output filename="ios_today_extension_strings_bg.pak" type="data_package" lang="bg" />
     <output filename="ios_today_extension_strings_bn.pak" type="data_package" lang="bn" />
     <output filename="ios_today_extension_strings_ca.pak" type="data_package" lang="ca" />
     <output filename="ios_today_extension_strings_cs.pak" type="data_package" lang="cs" />
@@ skipping 146 matching lines @@
       </message>
       <message name="IDS_IOS_PYSICAL_WEB_TURN_ON_TODAY_EXTENSION_FOOTER_LABEL" desc="The text contained in the button to enable physical web. [15em]">
         Enable
       </message>
       <message name="IDS_IOS_VOICE_SEARCH_TODAY_EXTENSION_TITLE" desc="The title for Voice Search button in today extension [Length: 20em]">
         Voice Search
       </message>
     </messages>
   </release>
 </grit>