sc a11y: Pass OAccessible for ScAccessibleDocumentPagePreview parent

Switch the parent param in the ctor to the more concrete
OAccessible class instead of using the abstract
XAccessible UNO interface.

Change-Id: Icd70a68745e06adb4d85907f84a1f776fe472132
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/210666
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

sc/source/ui/Accessibility/AccessibleDocumentPagePreview.cxx

@@ -1116,9 +1116,9 @@ ScPagePreviewCountData::ScPagePreviewCountData( const ScPreviewLocationData& rDa
 }
 
 ScAccessibleDocumentPagePreview::ScAccessibleDocumentPagePreview(
-        const uno::Reference<XAccessible>& rxParent, ScPreviewShell* pViewShell ) :
-    ScAccessibleDocumentBase(rxParent),
-    mpViewShell(pViewShell)
+    const rtl::Reference<comphelper::OAccessible>& rpParent, ScPreviewShell* pViewShell)
+    : ScAccessibleDocumentBase(rpParent)
+    , mpViewShell(pViewShell)
 {
     if (pViewShell)
         pViewShell->AddAccessibilityObject(*this);

sc/source/ui/inc/AccessibleDocumentPagePreview.hxx

@@ -35,9 +35,9 @@ class ScAccessibleDocumentPagePreview final
     :   public ScAccessibleDocumentBase
 {
 public:
-    ScAccessibleDocumentPagePreview(
-        const css::uno::Reference<css::accessibility::XAccessible>& rxParent,
-        ScPreviewShell* pViewShell );
+    ScAccessibleDocumentPagePreview(const rtl::Reference<comphelper::OAccessible>& rpParent,
+                                    ScPreviewShell* pViewShell);
+
 protected:
     virtual ~ScAccessibleDocumentPagePreview() override;