Addtional tests in options.dart to cover 'log' case, and other missed flag tests as they were added.

pkg/analyzer/test/error_test.dart

Index: pkg/analyzer/test/error_test.dart
diff --git a/pkg/analyzer/test/error_test.dart b/pkg/analyzer/test/error_test.dart
index 7a91029f038a897f64a389a099d399ad941e38aa..07befe7151dea186b6095c44a4b67c5e856f801c 100644
--- a/pkg/analyzer/test/error_test.dart
+++ b/pkg/analyzer/test/error_test.dart
@@ -13,6 +13,12 @@ void main() {
         isNull);
   });
 
+  test("an empty Dart file doesn't throw any errors", () {
+      expect(
+          errorsForFile(''),
+          isNull);
+    });
+
   test("an error on the first line", () {
     expect(errorsForFile('void foo;\n'),
         equals("Error in test.dart: Variables cannot have a type of 'void'\n"));