The flash is appearing as pre-installed on google chrome, however is possible the ability to allow or deny the execution of it on the websites, I already downloaded the installer again but when I click on run nothing happens, that is, it is not possible to install and it does not appear in the list of applications, in mozilla firefox there is no Shockwave Flash option in plugins.
The browser prompts the user to allow Flash if it detects the content requires Flash. If the content's Flash detection scripts don't conform to the browser requirements, the browser can't detect the content requires Flash and won't prompt the user to allow Flash. See Google's tech note, https://support.google.com/chrome/answer/6258784 for assistane.
Flash Player is a browser plugin, it will not display in the list of applications
Firefox and Chrome use different plugin technologies. Firefox usese NPAPI plugin, and Chrome uses PPAPI plugin. They are not interchangeable. Sounds like you may not have the NPAPI plugin installed. To install the NPAPI plugin, launch Firefox and navigate to https://get.adobe.com/flashplayer. The download page has OS/browser detection scripts to offer the appropriate plugin for the OS/browser is use.
You can disable the flash in your browser.
It is actually disabled by default. When certain content on the browser needs to use the plugin, the browser prompts the user to enable the flash player plugin.
I hope this information helps!