Issue 3223. Don't warn about types compatibility is one of the types was inferred

compiler/java/com/google/dart/compiler/type/InferredType.java

Index: compiler/java/com/google/dart/compiler/type/InferredType.java
diff --git a/compiler/java/com/google/dart/compiler/type/InferredType.java b/compiler/java/com/google/dart/compiler/type/InferredType.java
new file mode 100644
index 0000000000000000000000000000000000000000..e5ea3516fe59db9f9880692cab6c71368008b95a
--- /dev/null
+++ b/compiler/java/com/google/dart/compiler/type/InferredType.java
@@ -0,0 +1,34 @@
+// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+package com.google.dart.compiler.type;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+
+/**
+ * Marker interface for {@link Type} which means that this {@link Type} was not specified by user,
+ * but instead inferred from context.
+ */
+public interface InferredType {
+  public static class Helper {
+    /**
+     * @return the mix of the given {@link Type} interface and {@link InferredType}.
+     */
+    public static Type make(final Type type) {
+      if (type instanceof InterfaceType) {
+        return (Type) Proxy.newProxyInstance(type.getClass().getClassLoader(), new Class<?>[] {

[Brian Wilkerson, 2012/05/29 20:25:46]

Long term, I'm fairly certain that we don't want this implementation, but it's
very clever, so I'm fine with leaving it as a short-term solution.

+            InterfaceType.class,
+            InferredType.class}, new InvocationHandler() {
+          @Override
+          public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+            return method.invoke(type, args);
+          }
+        });
+      }
+      return type;
+    }
+  }
+}