Use failedAt in more places

pkg/compiler/lib/src/resolution/member_impl.dart

 // 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.
 
 part of dart2js.resolution.compute_members;
 
 class DeclaredMember implements Member {
   final Name name;
   final Element element;
   final ResolutionInterfaceType declarer;
@@ skipping 125 matching lines @@
 
   Member get implementation => this;
 
   ResolutionDartType get type => declaration.type.substByContext(instance);
 
   ResolutionFunctionType get functionType {
     return declaration.functionType.substByContext(instance);
   }
 
   DeclaredMember inheritFrom(ResolutionInterfaceType newInstance) {
-    assert(invariant(declaration.element, () {
+    assert(() {
       // Assert that if [instance] contains type variables, then these are
       // defined in the declaration of [newInstance] and will therefore be
       // substituted into the context of [newInstance] in the created member.
       ClassElement contextClass = Types.getClassContext(instance);
       return contextClass == null || contextClass == newInstance.element;
-    }, message: () {
-      return "Context mismatch: Context class "
-          "${Types.getClassContext(instance)} from $instance does match "
-          "the new instance $newInstance.";
-    }));
+    },
+        failedAt(
+            declaration.element,
+            "Context mismatch: Context class "
+            "${Types.getClassContext(instance)} from $instance does match "
+            "the new instance $newInstance."));
     return _newInheritedMember(newInstance);
   }
 
   InheritedMember _newInheritedMember(ResolutionInterfaceType newInstance) {
     return new InheritedMember(
         declaration, instance.substByContext(newInstance));
   }
 
   Iterable<Member> get declarations => <Member>[this];
 
@@ skipping 79 matching lines @@
 
   bool get isGetter => false;
 
   bool get isMethod => false;
 
   bool get isMalformed => true;
 
   String toString() => "erroneous member '$name' synthesized "
       "from ${inheritedMembers}";
 }