Avoid redundant calls to "pub list" when multiple dependencies change.

pkg/analysis_server/test/domain_completion_test.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 test.domain.completion;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/channel/channel.dart';
 import 'package:analysis_server/src/constants.dart';
 import 'package:analysis_server/src/domain_analysis.dart';
 import 'package:analysis_server/src/domain_completion.dart';
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/completion/completion_manager.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
 import 'package:analysis_server/src/services/index/index.dart' show Index;
 import 'package:analysis_server/src/services/index/local_memory_index.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
+import 'package:analysis_server/src/source/optimizing_pub_package_map_provider.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
-import 'package:analyzer/source/package_map_provider.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:unittest/unittest.dart';
 
 import 'analysis_abstract.dart';
 import 'mock_sdk.dart';
 import 'mocks.dart';
 import 'reflective_tests.dart';
 
@@ skipping 558 matching lines @@
   SourceFactory sourceFactory = DEFAULT_SOURCE_FACTORY;
 
   MockContext() {
     mockStream = new MockStream<SourcesChangedEvent>();
   }
 
   @override
   Stream<SourcesChangedEvent> get onSourcesChanged => mockStream;
 
   @override
+  bool exists(Source source) {
+    return source != null && source.exists();
+  }
+
+  @override
   TimestampedData<String> getContents(Source source) {
     return source.contents;
   }
 
-  @override
-  bool exists(Source source) {
-    return source != null && source.exists();
-  }
-
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
 /**
  * Mock stream for tracking calls to listen and subscription.cancel.
  */
 class MockStream<E> implements Stream<E> {
   MockSubscription<E> mockSubscription = new MockSubscription<E>();
   int listenCount = 0;
 
@@ skipping 20 matching lines @@
     return new Future.value(true);
   }
 
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
 class Test_AnalysisServer extends AnalysisServer {
   final MockContext mockContext = new MockContext();
 
   Test_AnalysisServer(ServerCommunicationChannel channel,
-      ResourceProvider resourceProvider, PackageMapProvider packageMapProvider,
+      ResourceProvider resourceProvider, OptimizingPubPackageMapProvider packageMapProvider,
       Index index, AnalysisServerOptions analysisServerOptions,
       DartSdk defaultSdk, InstrumentationService instrumentationService)
       : super(channel, resourceProvider, packageMapProvider, index,
           analysisServerOptions, defaultSdk, instrumentationService);
 
   @override
   AnalysisContext getAnalysisContext(String path) {
     return mockContext;
   }
 
@@ skipping 48 matching lines @@
 }
     ''');
     await waitForTasksFinished();
     Request request =
         new CompletionGetSuggestionsParams(testFile, 0).toRequest('0');
     Response response = handler.handleRequest(request);
     expect(response.error, isNotNull);
     expect(response.error.code, RequestErrorCode.NO_INDEX_GENERATED);
   }
 }