Canvas elements are not displayed in PDF export on Chrome and Edge

STEPS TO REPRODUCE

1. Access the XWiki instance with Chrome and/or Edge
2. Install PDF Export Application and Chart.JS Integration
3. Add some Chart.JS charts into a page (e.g. insert in Wiki/Source:

   (% id="multipleDataSets" %)
   |=Issue Type|=CKEditor|=Diagram
   |Bug|23|34
   |Improvement|17|11
   |New Feature|5|6
   
   {{tableToChartJS type="doughnut" table="multipleDataSets" multipleDataSets="true" /}}
   
   (% id="singleDataSet" %)
   |=Issue Type|=Count
   |Bug|23
   |Improvement|17
   |New Feature|5
   
   {{tableToChartJS type="polarArea" table="singleDataSet" /}}
   
   (% id="multipleDataSetsLine" %)
   |=Month|=2016|=2017
   |January|65|61
   |February|59|73
   |March|80|82
   |April|81|69
   |May|56|70
   |June|55|58
   |July|40|47
   
   {{tableToChartJS type="line" table="multipleDataSetsLine" multipleDataSets="true"/}}
   
   {{chartjs type="pie"
     options="{~"backgroundColors~": [~"#ff16e8~", ~"#0018f4~",~"#065d00~"]}"}}
   {
     "labels": [
       "Bug",
       "Improvement",
       "New Feature"
     ],
     "datasets": [{
       "label": "CKEditor",
       "data": [23, 17, 5]
     }, {
       "label": "Diagram",
       "data": [34, 11, 6]
     }]
   }
   {{/chartjs}}

4. Save the page
5. Export the page as PDF

EXPECTED RESULTS

The charts are visible in the exported PDF.

ACTUAL RESULTS

Some "broken" icons are displayed instead.

The issue reproduces only on Chrome and Edge browsers. On Firefox, currently, some white space is displayed because of CHARTJS-34.