Merge pull request #331 from Unity-Technologies/bugfixes/andrewm/invisible_button_activation

Fix for the menu button being able to be closed

Author: AndrewTHEManeri

Menus/ToolsMenu/ToolsMenuButton/ToolsMenuButton.cs

@@ -519,6 +519,10 @@ void OnBackgroundButtonClick()
 
 		void OnSecondaryButtonClicked()
 		{
+			if (!implementsSecondaryButton)
+			{
+				return;
+			}
 			this.RestartCoroutine(ref m_VisibilityCoroutine, AnimateHideAndDestroy());
 			closeButton();
 			ActionButtonHoverExit();