Cleanup: Remove Dispatcher and UserScript classes from builds where extensions are disabled.

extensions/renderer/BUILD.gn

Index: extensions/renderer/BUILD.gn
diff --git a/extensions/renderer/BUILD.gn b/extensions/renderer/BUILD.gn
index 46a1ed99f3a720540356211aec0214bf01d82cdd..6f47c91c2401873a66c1b0810a936a2825e01b86 100644
--- a/extensions/renderer/BUILD.gn
+++ b/extensions/renderer/BUILD.gn
@@ -163,8 +163,16 @@ source_set("renderer") {
     sources -= [
       "api_definitions_natives.cc",
       "context_menus_custom_bindings.cc",
+      "dispatcher.cc",
+      "dispatcher.h",
       "render_view_observer_natives.cc",
       "send_request_natives.cc",
+      "user_script_injector.cc",
+      "user_script_injector.h",
+      "user_script_set.cc",
+      "user_script_set.h",
+      "user_script_set_manager.cc",
+      "user_script_set_manager.h",
     ]
   }