[ios] Removed keyCode from FormActivityRegistered API.

ios/web/web_state/web_state_observer_bridge.mm

Index: ios/web/web_state/web_state_observer_bridge.mm
diff --git a/ios/web/web_state/web_state_observer_bridge.mm b/ios/web/web_state/web_state_observer_bridge.mm
index 292470c79e8cdbd45869f02bea65a2f51cb57d04..4ff34c2d89cc9b89ba5bc4b2f1a66a464cadf4c5 100644
--- a/ios/web/web_state/web_state_observer_bridge.mm
+++ b/ios/web/web_state/web_state_observer_bridge.mm
@@ -85,14 +85,12 @@ void WebStateObserverBridge::FormActivityRegistered(
     const std::string& field_name,
     const std::string& type,
     const std::string& value,
-    int key_code,
     bool input_missing) {
   SEL selector = @selector(webState:
       didRegisterFormActivityWithFormNamed:
                                  fieldName:
                                       type:
                                      value:
-                                   keyCode:
                               inputMissing:);
   if ([observer_ respondsToSelector:selector]) {
     [observer_ webState:web_state()
@@ -100,7 +98,6 @@ void WebStateObserverBridge::FormActivityRegistered(
                                    fieldName:field_name
                                         type:type
                                        value:value
-                                     keyCode:key_code
                                 inputMissing:input_missing];
   }
 }