Basic dart^2 analyzer tests running.

editor/util/plugins/com.google.dart.java2dart/resources/java_io.dart

Index: editor/util/plugins/com.google.dart.java2dart/resources/java_io.dart
diff --git a/editor/util/plugins/com.google.dart.java2dart/resources/java_io.dart b/editor/util/plugins/com.google.dart.java2dart/resources/java_io.dart
index d0459a0bef2b4d6a0b6ca09442f33f8a7d24716b..7799d49811be3cb841ae513cf90f2c472cc10ca5 100644
--- a/editor/util/plugins/com.google.dart.java2dart/resources/java_io.dart
+++ b/editor/util/plugins/com.google.dart.java2dart/resources/java_io.dart
@@ -72,8 +72,17 @@ class JavaFile {
   }
   String getPath() => _path.toNativePath();
   String getName() => _path.filename;
-  String getParent() => _path.directoryPath.toNativePath();
-  JavaFile getParentFile() => new JavaFile(getParent());
+  String getParent() {
+    var result = _path.directoryPath.toNativePath();
+    // "." or  "/" or  "C:\"
+    if (result.length < 4) return null;
+    return result;
+  }
+  JavaFile getParentFile() {
+    var parent = getParent();
+    if (parent == null) return null;
+    return new JavaFile(parent);
+  }
   String getAbsolutePath() => _path.canonicalize().toNativePath();
   String getCanonicalPath() => _path.canonicalize().toNativePath();
   JavaFile getAbsoluteFile() => new JavaFile(getAbsolutePath());