Distinguish null IDBKey (no value) and invalid IDBKey (value is not valid key)

content/common/indexed_db/indexed_db_param_traits.cc

Index: content/common/indexed_db/indexed_db_param_traits.cc
diff --git a/content/common/indexed_db/indexed_db_param_traits.cc b/content/common/indexed_db/indexed_db_param_traits.cc
index af33b1d87a58e9135fb7cb0163d042bd8cdbcf5c..34dfde579925c35a7034329ae1d934e526afb235 100644
--- a/content/common/indexed_db/indexed_db_param_traits.cc
+++ b/content/common/indexed_db/indexed_db_param_traits.cc
@@ -62,9 +62,7 @@ void ParamTraits<IndexedDBKey>::Write(Message* m, const param_type& p) {
       WriteParam(m, p.number());
       return;
     case WebKit::WebIDBKey::InvalidType:
-    default:
-      // TODO(jsbell): Remove "default" label once WebKit bug 76487 has rolled.
-      // http://crbug.com/110956
+    case WebKit::WebIDBKey::NullType:
       return;
   }
   NOTREACHED();
@@ -111,11 +109,11 @@ bool ParamTraits<IndexedDBKey>::Read(const Message* m,
         return true;
       }
     case WebKit::WebIDBKey::InvalidType:
-    default:
-      // TODO(jsbell): Remove "default" label once WebKit bug 76487 has rolled.
-      // http://crbug.com/110956
       r->SetInvalid();
       return true;
+    case WebKit::WebIDBKey::NullType:
+      r->SetNull();
+      return true;
   }
   NOTREACHED();
   return false;