Issue 3280. Fix for using function alias type as type variable bounds

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

Index: compiler/java/com/google/dart/compiler/type/Types.java
diff --git a/compiler/java/com/google/dart/compiler/type/Types.java b/compiler/java/com/google/dart/compiler/type/Types.java
index 163e862baf401368ac7a14011c9c68218c1b73d6..83dfd691dab34e7ab91ba02de0aabe727d143eed 100644
--- a/compiler/java/com/google/dart/compiler/type/Types.java
+++ b/compiler/java/com/google/dart/compiler/type/Types.java
@@ -163,6 +163,13 @@ public class Types {
     if (isSubtypeOfInterface(t, s)) {
       return true;
     }
+    if (t.getKind() == TypeKind.VARIABLE) {
+      Type bound = ((TypeVariable) t).getTypeVariableElement().getBound();
+      if (bound != null) {
+        return isSubtype(bound, s);
+      }
+      return true;
+    }
     if (t.getKind().equals(TypeKind.FUNCTION_ALIAS)) {
       return isSubtypeOfFunction(asFunctionType((FunctionAliasType) t), asFunctionType(s));
     }