convert engine element setter to completion element setter

pkg/analysis_server/test/computer/element_test.dart

Index: pkg/analysis_server/test/computer/element_test.dart
diff --git a/pkg/analysis_server/test/computer/element_test.dart b/pkg/analysis_server/test/computer/element_test.dart
index 5539c22eb3134aa68ba4e04c9fb8e20da477ef43..d8765b3fade73eba7ded7919420dd5cf90cda142 100644
--- a/pkg/analysis_server/test/computer/element_test.dart
+++ b/pkg/analysis_server/test/computer/element_test.dart
@@ -283,6 +283,32 @@ class A {
     expect(element.flags, Element.FLAG_STATIC);
   }
 
+  void test_fromElement_SETTER() {
+    Source source = addSource('/test.dart', '''
+class A {
+  set mySetter(String x) {}
+}''');
+    CompilationUnit unit = resolveLibraryUnit(source);
+    engine.FieldElement engineFieldElement =
+        findElementInUnit(unit, 'mySetter', engine.ElementKind.FIELD);

[Brian Wilkerson, 2014/09/16 22:47:46]

The "engine.ElementKind.FIELD" argument looks strange, both because it's there
and because it isn't "engine.ElementKind.SETTER". But I'm not familiar enough
with these tests to know whether it's a problem.

[danrubel, 2014/09/16 23:12:30]

I was surprised as well, but my current understanding is that the element model
represents the synthetic field updated by the setter, thus the setter is
attached to and accessed via that field.

+    engine.PropertyAccessorElement engineElement = engineFieldElement.setter;
+    // create notification Element
+    Element element = new Element.fromEngine(engineElement);
+    expect(element.kind, ElementKind.SETTER);
+    expect(element.name, 'mySetter');
+    {
+      Location location = element.location;
+      expect(location.file, '/test.dart');
+      expect(location.offset, 16);
+      expect(location.length, 'mySetter'.length);
+      expect(location.startLine, 2);
+      expect(location.startColumn, 7);
+    }
+    expect(element.parameters, '(String x)');
+    expect(element.returnType, isNull);
+    expect(element.flags, 0);
+  }
+
   void test_fromElement_dynamic() {
     var engineElement = engine.DynamicElementImpl.instance;
     // create notification Element