Dart2js deferred loading. Follow types of functions when calculating dependencies.

pkg/compiler/lib/src/typechecker.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;
 
 class TypeCheckerTask extends CompilerTask {
   TypeCheckerTask(Compiler compiler) : super(compiler);
   String get name => "Type checker";
 
@@ skipping 894 matching lines @@
       if (parameterTypes.moveNext()) {
         error = true;
         // TODO(johnniwinther): Provide better information on the called
         // function.
         reportTypeWarning(send, MessageKind.MISSING_ARGUMENT,
             {'argumentType': parameterTypes.current});
       }
       if (error) {
         // TODO(johnniwinther): Improve access to declaring element and handle
         // synthesized member signatures. Currently function typed instance
-        // members provide no access to there own name.
+        // members provide no access to their own name.
         if (element == null) {
           element = type.element;
-        } else if (type.element.isTypedef) {
-          if (element != null) {
-            reportTypeInfo(element,
-                           MessageKind.THIS_IS_THE_DECLARATION,
-                           {'name': element.name});
-          }
+        } else if (type.isTypedef) {
+          reportTypeInfo(element,
+              MessageKind.THIS_IS_THE_DECLARATION,
+              {'name': element.name});
           element = type.element;
         }
-        reportTypeInfo(element, MessageKind.THIS_IS_THE_METHOD);
+        if (element != null) {
+          reportTypeInfo(element, MessageKind.THIS_IS_THE_METHOD);
+        }
       }
     } else {
       while(!arguments.isEmpty) {
         DartType argumentType = analyze(arguments.head);
         if (argumentTypes != null) argumentTypes.addLast(argumentType);
         arguments = arguments.tail;
       }
     }
   }
 
@@ skipping 910 matching lines @@
 
   visitTypedef(Typedef node) {
     // Do not typecheck [Typedef] nodes.
   }
 
   visitNode(Node node) {
     compiler.internalError(node,
         'Unexpected node ${node.getObjectDescription()} in the type checker.');
   }
 }