Hello. I created a button on the form:

<?xml version="1.0" encoding="utf-8" ?>
<odoo>
    <data>
         <record id="button_for_pdf" model="ir.ui.view">
           <field name="name">Product Product Inherit Button</field>
           <field name="model">product.product</field>
           <field name="inherit_id" ref="product.product_normal_form_view"/>
           <field name="arch" type="xml">
               <header>
               <button name="open_pdf" type="object" string="Open PDF" style="width:200px"/>
            </header>
           </field>
      </record>
    </data>
</odoo>

This button should open the pdf file in the browser

class customize_template_for_product(models.Model):
    _inherit = 'product.product'
    
    @api.multi
    def open_pdf(self):

        param = [self.display_name, 'application/pdf']
        sql = 'Select checksum from ir_attachment where res_name=%s and mimetype=%s'
        self._cr.execute(sql, param)
        checksum = self._cr.fetchall()

        #if binary[0][0] is None:
         #   return

        path = self.env['ir.attachment']._get_path('', checksum[0][0])

        webbrowser.register('Chrome', None, webbrowser.BackgroundBrowser('C:\Program Files ('
                                                                             'x86)\Google\Chrome\Application\chrome.exe'))
        webbrowser.get('Chrome').open_new(path[1])

But this browser only opens on the computer where the server is installed with Odoo :(( 

How to make it open only at the client who called it?(Pressed the button) Thx...

... or open with widget="pdf_viewer" ?