Support multiple serialization sources in DeserializerSystemImpl.

pkg/compiler/lib/src/serialization/system.dart

 // Copyright (c) 2016, 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 dart2js.serialization_system;
 
 import 'dart:async';
 import '../commandline_options.dart';
 import '../common.dart';
 import '../common/backend_api.dart';
@@ skipping 10 matching lines @@
 import '../universe/world_impact.dart';
 import '../universe/use.dart';
 import 'json_serializer.dart';
 import 'modelz.dart';
 import 'resolved_ast_serialization.dart';
 import 'serialization.dart';
 import 'task.dart';
 
 class DeserializerSystemImpl extends DeserializerSystem {
   final Compiler _compiler;
-  final Deserializer _deserializer;
+  final DeserializationContext deserializationContext;
   final List<LibraryElement> deserializedLibraries = <LibraryElement>[];
   final ResolutionImpactDeserializer _resolutionImpactDeserializer;
   final ResolvedAstDeserializerPlugin _resolvedAstDeserializer;
   final ImpactTransformer _impactTransformer;
 
-  factory DeserializerSystemImpl(Compiler compiler, Deserializer deserializer,
-      ImpactTransformer impactTransformer) {
-    List<DeserializerPlugin> plugins = <DeserializerPlugin>[];
+  factory DeserializerSystemImpl(
+      Compiler compiler, ImpactTransformer impactTransformer) {
+    DeserializationContext context = new DeserializationContext();
     DeserializerPlugin backendDeserializer =
         compiler.backend.serialization.deserializer;
-    deserializer.plugins.add(backendDeserializer);
+    context.plugins.add(backendDeserializer);
     ResolutionImpactDeserializer resolutionImpactDeserializer =
         new ResolutionImpactDeserializer(backendDeserializer);
-    deserializer.plugins.add(resolutionImpactDeserializer);
+    context.plugins.add(resolutionImpactDeserializer);
     ResolvedAstDeserializerPlugin resolvedAstDeserializer =
         new ResolvedAstDeserializerPlugin(
             compiler.parsingContext, backendDeserializer);
-    deserializer.plugins.add(resolvedAstDeserializer);
-    return new DeserializerSystemImpl._(
-        compiler,
-        deserializer,
-        impactTransformer,
-        resolutionImpactDeserializer,
-        resolvedAstDeserializer);
+    context.plugins.add(resolvedAstDeserializer);
+    return new DeserializerSystemImpl._(compiler, context, impactTransformer,
+        resolutionImpactDeserializer, resolvedAstDeserializer);
   }
 
   DeserializerSystemImpl._(
       this._compiler,
-      this._deserializer,
+      this.deserializationContext,
       this._impactTransformer,
       this._resolutionImpactDeserializer,
       this._resolvedAstDeserializer);
 
   @override
   Future<LibraryElement> readLibrary(Uri resolvedUri) {
-    LibraryElement library = _deserializer.lookupLibrary(resolvedUri);
+    LibraryElement library = deserializationContext.lookupLibrary(resolvedUri);
     if (library != null) {
       deserializedLibraries.add(library);
       return Future.forEach(library.compilationUnits,
           (CompilationUnitElement compilationUnit) {
         ScriptZ script = compilationUnit.script;
         return _compiler
             .readScript(script.readableUri)
             .then((Script newScript) {
           script.file = newScript.file;
           _resolvedAstDeserializer.sourceFiles[script.resourceUri] =
@@ skipping 168 matching lines @@
   }
 
   @override
   void onElement(Element element, ObjectDecoder getDecoder(String tag)) {
     ObjectDecoder decoder = getDecoder(RESOLVED_AST_TAG);
     if (decoder != null) {
       _decoderMap[element] = decoder;
     }
   }
 }