Backed out changeset 5c2e089e2163 (bug 1332444) for causing bug 1360402 a=backout

MozReview-Commit-ID: 6JCqiMZePxX

accessible/windows/msaa/AccessibleWrap.cpp

@@ -1428,8 +1428,11 @@ AccessibleWrap::GetIAccessibleFor(const VARIANT& aVarChild, bool* aIsDefunct)
   }
 
   // If the MSAA ID is not a chrome id then we already know that we won't
-  // find it here and should look remotely instead.
-  if (XRE_IsParentProcess() && !sIDGen.IsChromeID(varChild.lVal)) {
+  // find it here and should look remotely instead. This handles the case when
+  // accessible is part of the chrome process and is part of the xul browser
+  // window and the child id points in the content documents. Thus we need to
+  // make sure that it is never called on proxies.
+  if (XRE_IsParentProcess() && !IsProxy() && !sIDGen.IsChromeID(varChild.lVal)) {
     return GetRemoteIAccessibleFor(varChild);
   }
   MOZ_ASSERT(XRE_IsParentProcess() ||