Remove code supporting incremental compilation in dart2js

pkg/compiler/lib/src/native/enqueue.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.
 
 import 'dart:collection' show Queue;
 
 import '../common.dart';
 import '../common/backend_api.dart' show ForeignResolver;
 import '../common/resolution.dart' show Resolution;
 import '../compiler.dart' show Compiler;
@@ skipping 57 matching lines @@
 abstract class NativeEnqueuerBase implements NativeEnqueuer {
   static final RegExp _identifier = new RegExp(r'^[a-zA-Z_$][a-zA-Z0-9_$]*$');
 
   /// The set of all native classes.  Each native class is in [nativeClasses]
   /// and exactly one of [unusedClasses] and [registeredClasses].
   final Set<ClassElement> _nativeClasses = new Set<ClassElement>();
 
   final Set<ClassElement> _registeredClasses = new Set<ClassElement>();
   final Set<ClassElement> _unusedClasses = new Set<ClassElement>();
 
-  final Set<LibraryElement> processedLibraries;
-
   bool get hasInstantiatedNativeClasses => !_registeredClasses.isEmpty;
 
   final Set<ClassElement> nativeClassesAndSubclasses = new Set<ClassElement>();
 
   final Compiler compiler;
   final bool enableLiveTypeAnalysis;
 
   ClassElement _annotationCreatesClass;
   ClassElement _annotationReturnsClass;
   ClassElement _annotationJsNameClass;
 
   /// Subclasses of [NativeEnqueuerBase] are constructed by the backend.
   NativeEnqueuerBase(Compiler compiler, this.enableLiveTypeAnalysis)
-      : this.compiler = compiler,
-        processedLibraries = compiler.cacheStrategy.newSet();
+      : this.compiler = compiler;
 
   JavaScriptBackend get backend => compiler.backend;
   BackendHelpers get helpers => backend.helpers;
   Resolution get resolution => compiler.resolution;
 
   DiagnosticReporter get reporter => compiler.reporter;
   CommonElements get commonElements => compiler.commonElements;
 
   void onInstantiatedType(ResolutionInterfaceType type) {
     if (_unusedClasses.remove(type.element)) {
       _registeredClasses.add(type.element);
     }
   }
 
   WorldImpact processNativeClasses(Iterable<LibraryElement> libraries) {
     WorldImpactBuilderImpl impactBuilder = new WorldImpactBuilderImpl();
     _processNativeClasses(impactBuilder, libraries);
     return impactBuilder;
   }
 
   void _processNativeClasses(
       WorldImpactBuilder impactBuilder, Iterable<LibraryElement> libraries) {
-    if (compiler.options.hasIncrementalSupport) {
-      // Since [Set.add] returns bool if an element was added, this restricts
-      // [libraries] to ones that haven't already been processed. This saves
-      // time during incremental compiles.
-      libraries = libraries.where(processedLibraries.add);
-    }
     libraries.forEach(processNativeClassesInLibrary);
     if (helpers.isolateHelperLibrary != null) {
       processNativeClassesInLibrary(helpers.isolateHelperLibrary);
     }
     processSubclassesOfNativeClasses(libraries);
     if (!enableLiveTypeAnalysis) {
       _registerTypeUses(impactBuilder, _nativeClasses, 'forced');
     }
   }
 
@@ skipping 515 matching lines @@
     List<ClassEntity> directSubtypes =
         emitter.directSubtypes.putIfAbsent(superclass, () => <ClassEntity>[]);
     directSubtypes.add(cls);
   }
 
   void logSummary(log(message)) {
     log('Compiled ${_registeredClasses.length} native classes, '
         '${_unusedClasses.length} native classes omitted.');
   }
 }