Use WorldImpact for element dependencies in deferred_load

pkg/compiler/lib/src/use_unused_api.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.
 
 /// This file use methods that aren't used by dart2js.dart, but that we wish to
 /// keep anyway. This might be general API that isn't currently in use,
 /// debugging aids, or API only used for testing (see TODO below).
 
 library dart2js.use_unused_api;
 
 import '../compiler.dart' as api;
 
 import 'colors.dart' as colors;
 import 'compiler.dart' as compiler;
 import 'constants/constant_system.dart' as constants;
 import 'constants/constructors.dart' as constants;
 import 'constants/evaluation.dart' as constants;
 import 'constants/expressions.dart' as constants;
 import 'constants/values.dart' as constants;
 import 'cps_ir/cps_ir_builder.dart' as ir_builder;
 import 'cps_ir/cps_ir_builder_task.dart' as ir_builder;
 import 'tree_ir/tree_ir_nodes.dart' as tree_ir;
 import 'dart_types.dart' as dart_types;
 import 'dart2js.dart' as dart2js;
-import 'compiler.dart' as dart2jslib;
+import 'deferred_load.dart' as deferred;
 import 'diagnostics/source_span.dart' as diagnostics;
 import 'elements/elements.dart' as elements;
 import 'elements/modelx.dart' as modelx;
 import 'elements/visitor.dart' as elements_visitor;
 import 'filenames.dart' as filenames;
 import 'inferrer/type_graph_inferrer.dart' as type_graph_inferrer;
 import 'io/line_column_provider.dart' as io;
 import 'io/source_map_builder.dart' as io;
 import 'js/js.dart' as js;
 import 'js_backend/js_backend.dart' as js_backend;
@@ skipping 39 matching lines @@
   usedByTests();
   useElements();
   useIr(null);
   useCompiler(null);
   useTypes();
   useCodeEmitterTask(null);
   useScript(null);
   useProgramBuilder(null);
   useSemanticVisitor();
   useTreeVisitors();
+  useDeferred();
 }
 
 useApi([api.ReadStringFromUri uri, compiler.Compiler compiler]) {
   compiler.analyzeUri(null);
   new diagnostics.SourceSpan.fromNode(null, null);
 }
 
 class NullConstantConstructorVisitor
     extends constants.ConstantConstructorVisitor {
   @override
@@ skipping 156 matching lines @@
      ..forEachLine(null)
      ..getFirstElementsInLine(null)
      ..forEachColumn(null, null);
   provider.getOffset(null, null);
 }
 
 usedByTests() {
   // TODO(ahe): We should try to avoid including API used only for tests. In
   // most cases, such API can be moved to a test library.
   World world = null;
-  dart2jslib.Compiler compiler = null;
-  compiler.currentlyInUserCode();
   type_graph_inferrer.TypeGraphInferrer typeGraphInferrer = null;
   source_file_provider.SourceFileProvider sourceFileProvider = null;
   sourceFileProvider.getSourceFile(null);
   world.hasAnyUserDefinedGetter(null, null);
   world.subclassesOf(null);
   world.getClassHierarchyNode(null);
   world.getClassSet(null);
   world.haveAnyCommonSubtypes(null, null);
   typeGraphInferrer.getCallersOf(null);
   dart_types.Types.sorted(null);
@@ skipping 15 matching lines @@
   pce.copyWithEnclosing(null);
   pfe.copyWithEnclosing(null);
   l.forEachImport(null);
 }
 
 useIr(ir_builder.IrBuilder builder) {
   builder
     ..buildStringConstant(null);
 }
 
-useCompiler(dart2jslib.Compiler compiler) {
-  compiler.libraryLoader
+useCompiler(compiler.Compiler c) {
+  c.libraryLoader
       ..reset()
       ..resetAsync(null)
       ..lookupLibrary(null);
-  compiler.forgetElement(null);
-  compiler.backend.constantCompilerTask.copyConstantValues(null);
+  c.forgetElement(null);
+  c.backend.constantCompilerTask.copyConstantValues(null);
+  c.currentlyInUserCode();
+
 }
 
 useTypes() {
 }
 
 useCodeEmitterTask(js_emitter.CodeEmitterTask codeEmitterTask) {
   full.Emitter fullEmitter = codeEmitterTask.emitter;
   fullEmitter.clearCspPrecompiledNodes();
   fullEmitter.buildLazilyInitializedStaticField(null, isolateProperties: null);
 }
@@ skipping 17 matching lines @@
 
 class TreeVisitor1 extends tree_ir.ExpressionVisitor1
                       with tree_ir.StatementVisitor1 {
   noSuchMethod(inv) {}
 }
 
 useTreeVisitors() {
   new TreeVisitor1().visitExpression(null, null);
   new TreeVisitor1().visitStatement(null, null);
 }
+
+useDeferred([deferred.DeferredLoadTask task]) {
+  task.dump();
+}