CKEditor modal is centered to the editor instead of window

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X, 7.1.X, 7.2.X, Master
• Fix Version/s: 7.0.0 DXP FP94, 7.0.10.15 DXP SP15, 7.0.X, 7.1.10 DXP FP19, 7.1.10.5 SP5, 7.1.X, 7.2.10 DXP FP8, 7.2.10.3 DXP SP3, 7.2.X, 7.3.4 CE GA5, 7.3.10 DXP GA1, Master
• Component/s: CKEditor
• Labels:
  • ee-ts
  • liferay-dxp-70-sp15
  • liferay-dxp-71-sp5
  • liferay-dxp-72-sp3
  • liferay-fixpack-de-94-7010
  • liferay-fixpack-dxp-19-7110
  • liferay-fixpack-dxp-8-7210
• Branch Version/s:
  7.2.x, 7.1.x, 7.0.x
• Backported to Branch:
  Committed
• Fix Priority: 3
• Git Pull Request: https://github.com/liferay-frontend/liferay-portal/pull/188

Reproduction steps:
0) Start a vanilla Liferay bundle
1) Add this in the portal-ext.properties:

editor.wysiwyg.default=ckeditor
editor.wysiwyg.portal-impl.portlet.ddm.text_html.ftl=ckeditor

2) Start the server, login as Admin, go to Product Menu > Content > Web Content > Create a new Basic Web Content
3) Click on the Product Menu toggle icon to make the window full sized
4) Scroll a little upwards to see only the CKEditor toolbar at the bottom of the page
4) Click e.g. the "Flash" button in the CKEditor's toolbar

Expected Results
The modal appears vertically centered to the page's current position within the browser. 

Actual Results
The dialog is vertically centered to the CKEditor instead of the browser window as expected and partly hidden, as outside of the current window

 Reproduced on 7.0.x @ d3de9cbf0bb186529267331caa39a2d4e3b7c3c8f9e96d48deaa0568a8cf9165
 Reproduced on master @ aafc3972f5dec0941e87baeb42852d4a9032adab9701b625e0cfa07e0b5e062a