Bug 1613985 - Use default for equivalent-to-default constructors/dest…

…ructors in dom/simpledb. r=smaug

Depends on D66028

Differential Revision: https://phabricator.services.mozilla.com/D66029

--HG--
extra : moz-landing-system : lando

dom/simpledb/SDBResults.h

@@ -20,7 +20,7 @@ class SDBResult : public nsISDBResult {
   explicit SDBResult(const nsACString& aData);
 
  private:
-  virtual ~SDBResult() {}
+  virtual ~SDBResult() = default;
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSISDBRESULT