[ios] Removed keyCode from FormActivityRegistered API.

ios/web/public/web_state/web_state_observer.h

Index: ios/web/public/web_state/web_state_observer.h
diff --git a/ios/web/public/web_state/web_state_observer.h b/ios/web/public/web_state/web_state_observer.h
index d0b76cd98c7723ddf25564687af52a46422abd93..ca05867ab139aeb7f97f93913e38dbf65d42c69e 100644
--- a/ios/web/public/web_state/web_state_observer.h
+++ b/ios/web/public/web_state/web_state_observer.h
@@ -29,10 +29,6 @@ enum class PageLoadCompletionStatus : bool { SUCCESS = 0, FAILURE = 1 };
 // load events from WebState.
 class WebStateObserver {
  public:
-  // Key code associated to form events for which the key code is missing or
-  // irrelevant.
-  static int kInvalidFormKeyCode;
-
   // Returns the web state associated with this observer.
   WebState* web_state() const { return web_state_; }
 
@@ -77,12 +73,10 @@ class WebStateObserver {
 
   // Called when the user is typing on a form field, with |error| indicating if
   // there is any error when parsing the form field information.
-  // |key_code| may be kInvalidFormKeyCode if there is no key code.
   virtual void FormActivityRegistered(const std::string& form_name,
                                       const std::string& field_name,
                                       const std::string& type,
                                       const std::string& value,
-                                      int key_code,
                                       bool input_missing) {}
 
   // Invoked when new favicon URL candidates are received.