To my knowledge Chromium hasn't enabled Flash Player support yet. If/when they do, it will be using the PPAPI plugin.
Safari uses the NPAPI plugin. If the NPAPI plugin is installed, please ensure it is enabled in Safari, see Enable for Safari.
If you have Chrome browser installed, Google embeds Flash Player in Chrome and there is nothing to install, just ensure that it is enabled (Enable for Chrome).
Thank you for helping me but it did't work.
After installing Safari Flash Player and rebooting my Mac it didn't show up on plugins list. I can't enable it. It doesn't show up, it seems that even after I install it, it isn't really installed.