Piwik\Plugins\CoreAdminHome\Controller::uploadCustomLogo PHP Method

    public function uploadCustomLogo()
    {
        Piwik::checkUserHasSuperUserAccess();
        $this->checkTokenInUrl();
        $logo = new CustomLogo();
        $successLogo = $logo->copyUploadedLogoToFilesystem();
        $successFavicon = $logo->copyUploadedFaviconToFilesystem();
        if ($successLogo || $successFavicon) {
            return '1';
        }
        return '0';
    }