Adds the legacy KeyboardEvent.keyCode attribute for extension IMEs.

chrome/browser/extensions/api/input_ime/input_ime_api.cc

Index: chrome/browser/extensions/api/input_ime/input_ime_api.cc
diff --git a/chrome/browser/extensions/api/input_ime/input_ime_api.cc b/chrome/browser/extensions/api/input_ime/input_ime_api.cc
index f37bac06510c38e288f76d5b5e8783f448c3d15e..b46c95c405e60022e2247b36cc033855333efcb1 100644
--- a/chrome/browser/extensions/api/input_ime/input_ime_api.cc
+++ b/chrome/browser/extensions/api/input_ime/input_ime_api.cc
@@ -552,6 +552,7 @@ bool InputImeSendKeyEventsFunction::RunAsync() {
     event.type = input_ime::KeyboardEvent::ToString(key_data[i]->type);
     event.key = key_data[i]->key;
     event.code = key_data[i]->code;
+    event.key_code = key_data[i]->key_code;
     if (key_data[i]->alt_key)
       event.alt_key = *(key_data[i]->alt_key);
     if (key_data[i]->ctrl_key)