Update charted to 0.4.8 and roll

packages/csslib/lib/src/tokenizer_base.dart

Index: packages/csslib/lib/src/tokenizer_base.dart
diff --git a/packages/csslib/lib/src/tokenizer_base.dart b/packages/csslib/lib/src/tokenizer_base.dart
index 663c987d1312265407e2e4c80cf4aaf6410eef29..c2a448fd8e209ca5f1563f19d3270db33de4b966 100644
--- a/packages/csslib/lib/src/tokenizer_base.dart
+++ b/packages/csslib/lib/src/tokenizer_base.dart
@@ -55,8 +55,7 @@ abstract class TokenizerBase {
   int _index = 0;
   int _startIndex = 0;
 
-  TokenizerBase(this._file, this._text, this._inString,
-      [this._index = 0]);
+  TokenizerBase(this._file, this._text, this._inString, [this._index = 0]);
 
   Token next();
   int getIdentifierKind();
@@ -80,9 +79,9 @@ abstract class TokenizerBase {
     }
   }
 
-  int _peekChar() {
-    if (_index < _text.length) {
-      return _text.codeUnitAt(_index);
+  int _peekChar([int offset = 0]) {
+    if (_index + offset < _text.length) {
+      return _text.codeUnitAt(_index + offset);
     } else {
       return 0;
     }
@@ -101,6 +100,17 @@ abstract class TokenizerBase {
     }
   }
 
+  bool _nextCharsAreNumber(int first) {
+    if (TokenizerHelpers.isDigit(first)) return true;
+    var second = _peekChar();
+    if (first == TokenChar.DOT) return TokenizerHelpers.isDigit(second);
+    if (first == TokenChar.PLUS || first == TokenChar.MINUS) {
+      return TokenizerHelpers.isDigit(second) ||
+          (second == TokenChar.DOT && TokenizerHelpers.isDigit(_peekChar(1)));
+    }
+    return false;
+  }
+
   Token _finishToken(int kind) {
     return new Token(kind, _file.span(_startIndex, _index));
   }