Use typed RefactoringOptions in the Dart version of the protocol.

pkg/analysis_server/tool/spec/spec_input.html

Index: pkg/analysis_server/tool/spec/spec_input.html
diff --git a/pkg/analysis_server/tool/spec/spec_input.html b/pkg/analysis_server/tool/spec/spec_input.html
index 48a5ff2d4c5dde856048f4aa8104ccb3c7e0eb84..53c5056d05a5b13b7edbd834dc9c610630ccb9fe 100644
--- a/pkg/analysis_server/tool/spec/spec_input.html
+++ b/pkg/analysis_server/tool/spec/spec_input.html
@@ -1208,7 +1208,7 @@
             </p>
           </field>
           <field name="options" optional="true">
-            <ref>object</ref>
+            <ref>RefactoringOptions</ref>
             <p>
               Data used to provide values provided by the user. The
               structure of the data is dependent on the kind of
@@ -2487,6 +2487,13 @@
           </field>
         </object>
       </type>
+      <type name="RefactoringOptions">
+        <p>
+          An abstract superclass of all refactoring options.
+        </p>
+        <object>
+        </object>
+      </type>
       <type name="RefactoringMethodParameterKind">
         <p>
           An enumeration of the kinds of parameters.