Fix typo in StringCanonicalizer

pkg/front_end/lib/src/fasta/scanner/canonicalizer.dart

Index: pkg/front_end/lib/src/fasta/scanner/canonicalizer.dart
diff --git a/pkg/front_end/lib/src/fasta/scanner/canonicalizer.dart b/pkg/front_end/lib/src/fasta/scanner/canonicalizer.dart
index 1d481ca309c9b6b44f7a0800f7bb80ea5cb5d517..0848a081078eda53bbcf17b57020c4d12d48fea9 100644
--- a/pkg/front_end/lib/src/fasta/scanner/canonicalizer.dart
+++ b/pkg/front_end/lib/src/fasta/scanner/canonicalizer.dart
@@ -113,6 +113,6 @@ class StringCanonicalizer {
   }
 
   clear() {
-    _nodes = new List<Node>(size);
+    _nodes = new List<Node>(_size);
   }
 }