Remove ListValue::Append(raw ptr) on Mac and iOS

content/browser/accessibility/accessibility_tree_formatter_mac.mm

Index: content/browser/accessibility/accessibility_tree_formatter_mac.mm
diff --git a/content/browser/accessibility/accessibility_tree_formatter_mac.mm b/content/browser/accessibility/accessibility_tree_formatter_mac.mm
index 1d67d2d88fff98f17e5e28d05a9890ca8a9e1c2b..6da9ebf5bea06d71dc9b79b704ba399e382ff156 100644
--- a/content/browser/accessibility/accessibility_tree_formatter_mac.mm
+++ b/content/browser/accessibility/accessibility_tree_formatter_mac.mm
@@ -88,7 +88,7 @@ std::unique_ptr<base::Value> PopulateObject(id value);
 std::unique_ptr<base::ListValue> PopulateArray(NSArray* array) {
   std::unique_ptr<base::ListValue> list(new base::ListValue);
   for (NSUInteger i = 0; i < [array count]; i++)
-    list->Append(PopulateObject([array objectAtIndex:i]).release());
+    list->Append(PopulateObject([array objectAtIndex:i]));
   return list;
 }
 
@@ -253,11 +253,11 @@ void AccessibilityTreeFormatterMac::AddProperties(
     if (value != nil) {
       dict->Set(
           SysNSStringToUTF8(requestedAttribute),
-          PopulateObject(value).release());
+          PopulateObject(value));
     }
   }
-  dict->Set(kPositionDictAttr, PopulatePosition(node).release());
-  dict->Set(kSizeDictAttr, PopulateSize(cocoa_node).release());
+  dict->Set(kPositionDictAttr, PopulatePosition(node));
+  dict->Set(kSizeDictAttr, PopulateSize(cocoa_node));
 }
 
 base::string16 AccessibilityTreeFormatterMac::ToString(