Steps towards making dart2js JS AST templates an indepentent library.

pkg/compiler/lib/src/js/template.dart

Index: pkg/compiler/lib/src/js/template.dart
diff --git a/pkg/compiler/lib/src/js/template.dart b/pkg/compiler/lib/src/js/template.dart
index f08fe5239b4847576277eea271795f175b51ecae..ad772b2f0889c4178ff2c43d29e35f4521cb76f8 100644
--- a/pkg/compiler/lib/src/js/template.dart
+++ b/pkg/compiler/lib/src/js/template.dart
@@ -709,12 +709,12 @@ class InstantiatorGeneratorVisitor implements NodeVisitor<Instantiator> {
 }
 
 /**
- * InterpolatedNodeAnalysis extract [InterpolatedNode]s from AST.
+ * InterpolatedNodeAnalysis determines which AST trees contain
+ * [InterpolatedNode]s, and the names of the named interpolated nodes.
  */
 class InterpolatedNodeAnalysis extends BaseVisitor {
-  final Setlet<Node> containsInterpolatedNode = new Setlet<Node>();
-  final List<InterpolatedNode> interpolatedNodes = <InterpolatedNode>[];
-  final Setlet<String> holeNames = new Setlet<String>();
+  final Set<Node> containsInterpolatedNode = new Set<Node>();
+  final Set<String> holeNames = new Set<String>();
   int count = 0;
 
   InterpolatedNodeAnalysis();
@@ -734,7 +734,6 @@ class InterpolatedNodeAnalysis extends BaseVisitor {
   }
 
   visitInterpolatedNode(InterpolatedNode node) {
-    interpolatedNodes.add(node);
     containsInterpolatedNode.add(node);
     if (node.isNamed) holeNames.add(node.nameOrPosition);
     ++count;