Add StaticUse for more precise registration of statically known element use.

pkg/compiler/lib/src/deferred_load.dart

 // Copyright (c) 2014, 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.
 
 library deferred_load;
 
 import 'common.dart';
 import 'common/backend_api.dart' show
     Backend;
 import 'common/tasks.dart' show
@@ skipping 29 matching lines @@
     TreeElements;
 import 'tree/tree.dart' as ast;
 import 'tree/tree.dart' show
     Import,
     LibraryTag,
     LibraryDependency,
     LiteralDartString,
     LiteralString,
     NewExpression,
     Node;
+import 'universe/use.dart' show
+    StaticUse;
 import 'universe/world_impact.dart' show
     WorldImpact;
 import 'util/setlet.dart' show
     Setlet;
 import 'util/uri_extras.dart' as uri_extras;
 import 'util/util.dart' show
     Link, makeUnique;
 
 /// A "hunk" of the program that will be loaded whenever one of its [imports]
 /// are loaded.
@@ skipping 245 matching lines @@
       } else {
         // TODO(sigurdm): We want to be more specific about this - need a better
         // way to query "liveness".
         AstElement analyzableElement = element.analyzableElement.declaration;
         if (!compiler.enqueuer.resolution.hasBeenProcessed(analyzableElement)) {
           return;
         }
 
         WorldImpact worldImpact =
             compiler.resolution.getWorldImpact(analyzableElement);
-        elements.addAll(worldImpact.staticUses);
+        worldImpact.staticUses.forEach((StaticUse staticUse) {
+          elements.add(staticUse.element);
+        });
         elements.addAll(worldImpact.closures);
         for (DartType type in worldImpact.typeLiterals) {
           if (type.isTypedef || type.isInterfaceType) {
             elements.add(type.element);
           }
         }
         worldImpact.instantiatedTypes.forEach(collectTypeDependencies);
         worldImpact.isChecks.forEach(collectTypeDependencies);
         worldImpact.asCasts.forEach(collectTypeDependencies);
         worldImpact.onCatchTypes.forEach(collectTypeDependencies);
@@ skipping 656 matching lines @@
     return result;
   }
 
   bool operator ==(other) {
     if (other is! _DeclaredDeferredImport) return false;
     return declaration == other.declaration;
   }
 
   int get hashCode => declaration.hashCode * 17;
 }