Please review a test fix for an issue where the test fails citing
"Invalid HTML position" because pressing PAGE_DOWN does not cause the
document to scroll down to end of document.
This is because even though robot send PAGE_DOWN key events but the
focus is not in the editorpane so it does not scroll.
Proposed fix is to make sure the editorPane is in focus and caret is
present in the document so that robot PAGE_DOWN events by robot causes
it to scroll to end of document.