Simpler generic variables resolution.

lib/compiler/implementation/dart_backend/placeholder_collector.dart

Index: lib/compiler/implementation/dart_backend/placeholder_collector.dart
diff --git a/lib/compiler/implementation/dart_backend/placeholder_collector.dart b/lib/compiler/implementation/dart_backend/placeholder_collector.dart
index dd2ae79cde0d6451c296142635d866ed7e3f9442..52322394425f3b619685f9beda0fcaab0852d93e 100644
--- a/lib/compiler/implementation/dart_backend/placeholder_collector.dart
+++ b/lib/compiler/implementation/dart_backend/placeholder_collector.dart
@@ -327,23 +327,13 @@ class PlaceholderCollector extends AbstractVisitor {
   visitTypeAnnotation(TypeAnnotation node) {
     // Poor man generic variables resolution.
     // TODO(antonm): get rid of it once resolver can deal with it.
-    if (isPlainTypeName(node)) {
-      NodeList typeParameters = null;
-      if (currentElement is TypedefElement) {
-        Typedef typedefNode = currentElement.parseNode(compiler);
-        typeParameters = typedefNode.typeParameters;
-      }
-      if (currentElement is ClassElement) {
-        ClassNode classNode = currentElement.parseNode(compiler);
-        typeParameters = classNode.typeParameters;
-      }
-      if (typeParameters !== null) {
-        SourceString name = node.typeName.asIdentifier().source;
-        for (TypeVariable parameter in typeParameters) {
-          if (parameter.name.source == name) {
-            // type annotation matches one of parameters, shouldn't be renamed.
-            return;
-          }
+    if (isPlainTypeName(node) && currentElement is TypeDeclarationElement) {
+      SourceString name = node.typeName.asIdentifier().source;
+      TypeDeclarationElement typeElement = currentElement;
+      for (TypeVariableType parameter in typeElement.typeVariables) {
+        if (parameter.name == name) {
+          // type annotation matches one of parameters, shouldn't be renamed.
+          return;
         }
       }
     }