Use output_all_resource_defines=false in most grd files.

content/app/strings/content_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!-- This file contains definitions of resources that will be translated for
 each locale. Specifically, these are UI strings that are used by content that
 need to be translated for each locale.-->
 
 <!-- Some of these strings and string descriptions were taken from
 WebKit/win/WebCoreLocalizedStrings.cpp so we include the original license
 below:
 
@@ skipping 17 matching lines @@
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 -->
 
 <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>
     <!-- TODO add each of your output files.  Modify the three below, and add
     your own for your various languages.  See the user's guide
     (https://www.chromium.org/developers/tools-we-use-in-chromium/grit/grit-users-guide)
     for more details.
     Note that all output references are relative to the output directory
     which is specified at build time. -->
     <output filename="grit/content_strings.h" type="rc_header">
       <emit emit_type='prepend'></emit>
     </output>
@@ skipping 815 matching lines @@
         Off
       </message>
 
       <message name="IDS_PLUGIN_INITIALIZATION_ERROR" desc="A message displayed when a plugin failed to load">
         Couldn't load plugin.
       </message>
 
     </messages>
   </release>
 </grit>