  
  // The name of the preference that stores the promotion object.
  const char kPrefPromoObject[] = "promo";
+--- a/chrome/chrome_browser.gypi
++++ b/chrome/chrome_browser.gypi
+@@ -3450,6 +3450,9 @@
+         ['enable_session_service==1', {
+           'sources': [ '<@(chrome_browser_session_service_sources)' ],
+         }],
++        ['enable_hotwording==1', {
++          'defines': [ 'ENABLE_HOTWORDING' ],
++        }],
+         ['OS!="android" and OS!="ios" and chromeos==0', {
+           'sources': [ '<@(chrome_browser_desktop_sources)' ],
+         }],
 --- a/chrome/chrome_dll.gypi
 +++ b/chrome/chrome_dll.gypi
 @@ -92,6 +92,7 @@

 
 // The extension to use to replace the temporary one created when the SRT was
 // downloaded.
--- a/chrome/browser/services/gcm/gcm_account_tracker.cc
+++ b/chrome/browser/services/gcm/gcm_account_tracker.cc
@@ -17,9 +17,9 @@

       },
       'postbuilds' : [
         {
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -17,6 +17,11 @@
   import("//build/config/linux/pkg_config.gni")
 }
 
+declare_args() {
+  # 'Ok Google' hotwording is NOT enabled.
+  enable_hotwording = false
+}
+
 about_credits_file = "$target_gen_dir/about_credits.html"
 additional_modules_list_file =
     "$root_gen_dir/chrome/browser/internal/additional_modules_list.txt"
@@ -439,6 +444,10 @@
     }
   }
 
+  if (enable_hotwording) {
+    defines += [ "ENABLE_HOTWORDING" ]
+  }
+
   if (is_linux) {
     deps += [
       "//device/media_transfer_protocol",
--- a/chrome/browser/app_controller_mac.mm
+++ b/chrome/browser/app_controller_mac.mm
@@ -160,7 +160,7 @@
