Clean up dead code

tp-button.js

@@ -225,7 +225,6 @@ class TpButton extends EventHelpers(LitElement) {
         this.listen(this, 'click', '_submitOnTap');
         this.listen(this._form, 'submit', '_onFormSubmit');
         this.listen(this._form, 'invalid', '_onFormFailed');
-        this.listen(this._form, 'response', '_onFormSuccess');
       }
     }
   }
@@ -344,7 +343,7 @@ class TpButton extends EventHelpers(LitElement) {
   }
 
   _submitOnTap() {
-    if (this.submit && !this.isSubmitting) {
+    if (this.submit && !this.locked) {
       this._form.submitButton = this;
       this._form.submit();
     }
@@ -356,14 +355,6 @@ class TpButton extends EventHelpers(LitElement) {
     }
   }
 
-  _onFormSuccess() {
-    this.isSubmitting(false);
-
-    if (this.reactive) {
-      this.showSuccess();
-    }
-  }
-
   _onFormFailed(e) {
     // Only react if this button instance was the actual pressed button.
     // We have to check this in case the parent form has multiple submit buttons.
@@ -374,10 +365,8 @@ class TpButton extends EventHelpers(LitElement) {
         }
       }
 
-      this.isSubmitting = false;
-
       if (this.reactive) {
-        this.showError();
+        this.hideSpinner();
       }
     }
   }