Remove computeSignature from FunctionElement.

pkg/compiler/lib/src/dart_backend/backend.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 dart_backend;
 
 // TODO(ahe): This class is simply wrong.  This backend should use
 // elements when it can, not AST nodes.  Perhaps a [Map<Element,
 // TreeElements>] is what is needed.
 class ElementAst {
@@ skipping 278 matching lines @@
            !link.isEmpty;
            link = link.tail) {
         InterfaceType supertype = link.head;
         ClassElement superclass = supertype.element;
         LibraryElement library = superclass.library;
         if (library.isPlatformLibrary) {
           if (_userImplementedPlatformClasses.add(superclass)) {
             // Register selectors for all instance methods since these might
             // be called on user classes from within the platform
             // implementation.
-            superclass.forEachLocalMember((Element element) {
+            superclass.forEachLocalMember((MemberElement element) {
               if (element.isConstructor || element.isStatic) return;
 
               FunctionElement function = element.asFunctionElement();
-              if (function != null) {
-                function.computeSignature(compiler);
-              }
+              element.computeType(compiler);
               Selector selector = new Selector.fromElement(element);
               if (selector.isGetter) {
                 registry.registerDynamicGetter(selector);
               } else if (selector.isSetter) {
                 registry.registerDynamicSetter(selector);
               } else {
                 registry.registerDynamicInvocation(selector);
               }
             });
           }
@@ skipping 207 matching lines @@
 class _ElementAstCreationContext implements ElementAstCreationContext {
   final Compiler compiler;
   final ConstantSystem constantSystem;
 
   _ElementAstCreationContext(this.compiler, this.constantSystem);
 
   DartTypes get dartTypes => compiler.types;
 
   InternalErrorFunction get internalError => compiler.internalError;
 }