Impacted versions:
- 8.0

Steps to reproduce:
1. open Accounting / Configuration / Taxes / Tax Codes
2. open any Tax Code
3. press Print / Account Tax

Current behavior:

QWebException: "chart_tax_id" while evaluating
"get_lines(data['form']['based_on'], data['form']['company_id'], data['form']['chart_tax_id'])"
Details: http://paste.ubuntu.com/12689915/

Expected behavior:
- Tax Code report

Test on:
- different 8.0 instances
- runbot: http://105817-8-0-6b6d73.runbot8.odoo.com/web

addons/account/report/report_vat.py
def set_context(self, objects, data, ids, report_type=None):
        new_ids = ids
        res = {}
        if not data:
            company_id = self.pool['res.users'].browse(self.cr, self.uid, self.uid).company_id.id
            data = {
                'form': {
                    'based_on': 'invoices',
                    'company_id': company_id,
                    'display_detail': False,
                }
            }
        self.period_ids = []
        self.fiscalyear_id = False
        period_obj = self.pool.get('account.period')
        self.display_detail = data['form']['display_detail']
        res['periods'] = ''
        res['fiscalyear'] = data['form'].get('fiscalyear_id', False)
        self.fiscalyear_id = res['fiscalyear']
        if data['form'].get('period_from', False) and data['form'].get('period_to', False):
            self.period_ids = period_obj.build_ctx_periods(self.cr, self.uid, data['form']['period_from'], data['form']['period_to'])
            periods_l = period_obj.read(self.cr, self.uid, self.period_ids, ['name'])
            for period in periods_l:
                if res['periods'] == '':
                    res['periods'] = period['name']
                else:
                    res['periods'] += ", "+ period['name']
        return super(tax_report, self).set_context(objects, data, new_ids, report_type=report_type)
    def __init__(self, cr, uid, name, context=None):