diff -up chromium-94.0.4606.54/third_party/webrtc/BUILD.gn.fix-multiple-define chromium-94.0.4606.54/third_party/webrtc/BUILD.gn
--- chromium-94.0.4606.54/third_party/webrtc/BUILD.gn.fix-multiple-define	2021-09-24 13:22:48.067565858 -0400
+++ chromium-94.0.4606.54/third_party/webrtc/BUILD.gn	2021-09-24 13:23:10.163664830 -0400
@@ -119,10 +119,10 @@ config("common_inherited_config") {
   ldflags = []
 
   if (rtc_enable_symbol_export || is_component_build) {
-    defines = [ "WEBRTC_ENABLE_SYMBOL_EXPORT" ]
+    defines += [ "WEBRTC_ENABLE_SYMBOL_EXPORT" ]
   }
   if (rtc_enable_objc_symbol_export) {
-    defines = [ "WEBRTC_ENABLE_OBJC_SYMBOL_EXPORT" ]
+    defines += [ "WEBRTC_ENABLE_OBJC_SYMBOL_EXPORT" ]
   }
 
   if (build_with_mozilla) {