Mix in [TreeElementMixin] only on nodes that need it.

sdk/lib/_internal/compiler/implementation/resolution/registry.dart

Index: sdk/lib/_internal/compiler/implementation/resolution/registry.dart
diff --git a/sdk/lib/_internal/compiler/implementation/resolution/registry.dart b/sdk/lib/_internal/compiler/implementation/resolution/registry.dart
index 2dc496234c6efe9c54daf6d2bcda30cfef2b3cf4..cec5dd9519be1ca7c27902aa1232276f5e5dd0b2 100644
--- a/sdk/lib/_internal/compiler/implementation/resolution/registry.dart
+++ b/sdk/lib/_internal/compiler/implementation/resolution/registry.dart
@@ -31,13 +31,18 @@ class ResolutionRegistry extends Registry {
   //  Node-to-Element mapping functionality.
   //////////////////////////////////////////////////////////////////////////////
 
+  /// Register [node] as the declaration of [element].
+  void defineFunction(FunctionExpression node, FunctionElement element) {
+    mapping[node] = element;
+  }
+
   /// Register [node] as a reference to [element].
   Element useElement(Node node, Element element) {
     if (element == null) return null;
     return mapping[node] = element;
   }
 
-  /// Register [node] as a declaration of [element].
+  /// Register [node] as the declaration of [element].
   void defineElement(Node node, Element element) {
     mapping[node] = element;
   }
@@ -47,6 +52,17 @@ class ResolutionRegistry extends Registry {
     return mapping[node];
   }
 
+  /// Sets the loop variable of the for-in [node] to be [element].
+  void setForInVariable(ForIn node, Element element) {
+    mapping[node] = element;
+  }
+
+  /// Sets the target constructor [node] to be [element].
+  void setRedirectingTargetConstructor(RedirectingFactoryBody node,
+                                       ConstructorElement element) {
+    useElement(node, element);
+  }
+
   //////////////////////////////////////////////////////////////////////////////
   //  Node-to-Selector mapping functionality.
   //////////////////////////////////////////////////////////////////////////////
@@ -84,7 +100,6 @@ class ResolutionRegistry extends Registry {
   DartType useType(Node annotation, DartType type) {
     if (type != null) {
       mapping.setType(annotation, type);
-      useElement(annotation, type.element);
     }
     return type;
   }