Bug 1453873: Stop firing accessible focus events for JAWS when combo box options are selected. r=MarcoZ

These events were a hack implemented in bug 703198.
At that time, JAWS required focus events for selection changes in a collapsed combo box.
However, these events also fire for expanded combo boxes.
This is problematic with e10s because now, for an expanded combo box, the real focus events come from the XUL dropdown implemented in the parent process, which is not associated with the document a11y tree in any way.
JAWS seems to cope just fine with value changes for Firefox combo boxes now and VFO have agreed that this is the correct path forward.

MozReview-Commit-ID: Iefop25bFe0

--HG--
extra : rebase_source : a86e5d73d560853bb50e1d8e3bbd11431aba8eb0

accessible/windows/msaa/AccessibleWrap.cpp

@@ -1217,16 +1217,6 @@ AccessibleWrap::FireWinEvent(Accessible* aTarget, uint32_t aEventType)
 
   // Fire MSAA event for client area window.
   ::NotifyWinEvent(winEvent, hwnd, OBJID_CLIENT, childID);
-
-  // JAWS announces collapsed combobox navigation based on focus events.
-  if (aEventType == nsIAccessibleEvent::EVENT_SELECTION &&
-      Compatibility::IsJAWS()) {
-    roles::Role role = aTarget->IsProxy() ? aTarget->Proxy()->Role() :
-      aTarget->Role();
-    if (role == roles::COMBOBOX_OPTION) {
-      ::NotifyWinEvent(EVENT_OBJECT_FOCUS, hwnd, OBJID_CLIENT, childID);
-    }
-  }
 }
 
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