pkg/csslib: remove unused vars and fields

lib/src/tokenizer.dart

Index: lib/src/tokenizer.dart
diff --git a/lib/src/tokenizer.dart b/lib/src/tokenizer.dart
index ed616d2d88fcd03ae596cea7a357a6b50857dc67..f5c52104f7c2e79731335cfe937b706ca686af52 100644
--- a/lib/src/tokenizer.dart
+++ b/lib/src/tokenizer.dart
@@ -40,7 +40,7 @@ class Tokenizer extends TokenizerBase {
 
           _startIndex = _index;
           ch = _nextChar();
-          Token ident = finishIdentifier();
+          finishIdentifier();
 
           // Is it a directive?
           int tokId = TokenKind.matchDirectives(
@@ -260,7 +260,6 @@ class Tokenizer extends TokenizerBase {
   Token finishIdentifier() {
     // If we encounter an escape sequence, remember it so we can post-process
     // to unescape.
-    bool hasEscapedChars = false;
     var chars = [];
 
     // backup so we can start with the first character