Bug 377800. Too many warnings for accessibility in console. r=surkov

accessible/src/base/nsAccessibilityService.cpp

@@ -1001,7 +1001,9 @@ NS_IMETHODIMP nsAccessibilityService::GetAccessibleInWeakShell(nsIDOMNode *aNode
 nsresult nsAccessibilityService::InitAccessible(nsIAccessible *aAccessibleIn,
                                                 nsIAccessible **aAccessibleOut)
 {
-  NS_ENSURE_TRUE(aAccessibleIn, NS_ERROR_FAILURE);
+  if (!aAccessibleIn) {
+    return NS_ERROR_FAILURE; // No accessible to init
+  }
   NS_ASSERTION(aAccessibleOut && !*aAccessibleOut, "Out param should already be cleared out");
 
   nsCOMPtr<nsPIAccessNode> privateAccessNode = do_QueryInterface(aAccessibleIn);

accessible/src/base/nsAccessible.cpp

@@ -992,7 +992,9 @@ nsAccessible::GetState(PRUint32 *aState, PRUint32 *aExtraState)
   }
 
   nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
-  NS_ENSURE_TRUE(content, NS_ERROR_FAILURE);
+  if (!content) {
+    return NS_OK;  // On document, this is not an error
+  }
 
   // Set STATE_UNAVAILABLE state based on disabled attribute
   // The disabled attribute is mostly used in XUL elements and HTML forms, but