detect flutter and use default analysis options for flutter

pkg/analyzer/lib/src/generated/workspace.dart

Index: pkg/analyzer/lib/src/generated/workspace.dart
diff --git a/pkg/analyzer/lib/src/generated/workspace.dart b/pkg/analyzer/lib/src/generated/workspace.dart
index eeff673a644c39c92f21d835c2a40b987e2f5915..503472b4eb4b5476b1e6a655792ba76158c9d6f1 100644
--- a/pkg/analyzer/lib/src/generated/workspace.dart
+++ b/pkg/analyzer/lib/src/generated/workspace.dart
@@ -25,6 +25,12 @@ abstract class Workspace {
   UriResolver get packageUriResolver;
 
   /**
+   * Return `true` if this workspace defines a single "project"
+   * and that "project" depends upon flutter,
+   */
+  bool get hasFlutterDependency => false;
+
+  /**
    * Create the [SourceFactory] for resolving Uris to [Source]s.
    * The [sdk] may be `null`.
    */