Split scannerlib.dart into several libraries.

pkg/dart2js_incremental/lib/diff.dart

Index: pkg/dart2js_incremental/lib/diff.dart
diff --git a/pkg/dart2js_incremental/lib/diff.dart b/pkg/dart2js_incremental/lib/diff.dart
index a667fad05d82fa8f28fffcb9ad5dc8a8c8e3fc97..f4d381a7495beb8eb2886f6b76a7673aab72c2ac 100644
--- a/pkg/dart2js_incremental/lib/diff.dart
+++ b/pkg/dart2js_incremental/lib/diff.dart
@@ -19,13 +19,17 @@ import 'package:compiler/src/elements/modelx.dart' as modelx;
 import 'package:compiler/src/elements/modelx.dart' show
     DeclarationSite;
 
-import 'package:compiler/src/scanner/scannerlib.dart' show
+import 'package:compiler/src/scanner/class_element_parser.dart' show
+    PartialClassElement;
+
+import 'package:compiler/src/scanner/listener.dart' show
+    PartialElement;
+
+import 'package:compiler/src/scanner/token.dart' show
     EOF_TOKEN,
     ErrorToken,
     IDENTIFIER_TOKEN,
     KEYWORD_TOKEN,
-    PartialClassElement,
-    PartialElement,
     Token;
 
 class Difference {