Add DartSdk.getLinkedBundle() and use it in PubSummaryManager.

pkg/analyzer/lib/src/dart/sdk/sdk.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 analyzer.src.generated.sdk2;
 
 import 'dart:collection';
 import 'dart:io' as io;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 44 matching lines @@
   /**
    * The [AnalysisContext] which is used for all of the sources in this SDK.
    */
   InternalAnalysisContext _analysisContext;
 
   /**
    * The mapping from Dart URI's to the corresponding sources.
    */
   Map<String, Source> _uriToSourceMap = new HashMap<String, Source>();
 
+  PackageBundle _sdkBundle;
+
   /**
    * Set the [options] for this SDK analysis context.  Throw [StateError] if the
    * context has been already created.
    */
   void set analysisOptions(AnalysisOptions options) {
     if (_analysisContext != null) {
       throw new StateError(
           'Analysis options cannot be changed after context creation.');
     }
     _analysisOptions = options;
   }
 
   @override
   AnalysisContext get context {
     if (_analysisContext == null) {
       _analysisContext = new SdkAnalysisContext(_analysisOptions);
       SourceFactory factory = new SourceFactory([new DartUriResolver(this)]);
       _analysisContext.sourceFactory = factory;
       if (_useSummary) {
         bool strongMode = _analysisOptions?.strongMode ?? false;
-        PackageBundle sdkBundle = getSummarySdkBundle(strongMode);
+        PackageBundle sdkBundle = getLinkedBundle();
         if (sdkBundle != null) {
           _analysisContext.resultProvider = new SdkSummaryResultProvider(
               _analysisContext, sdkBundle, strongMode);
         }
       }
     }
     return _analysisContext;
   }
 
   @override
@@ skipping 48 matching lines @@
     try {
       return file.createSource(parseUriWithException(path));
     } on URISyntaxException catch (exception, stackTrace) {
       AnalysisEngine.instance.logger.logInformation(
           "Failed to create URI: $path",
           new CaughtException(exception, stackTrace));
     }
     return null;
   }
 
+  @override
+  PackageBundle getLinkedBundle() {
+    bool strongMode = _analysisOptions?.strongMode ?? false;
+    _sdkBundle ??= getSummarySdkBundle(strongMode);
+    return _sdkBundle;
+  }
+
   String getRelativePathFromFile(File file);
 
   @override
   SdkLibrary getSdkLibrary(String dartUri) => libraryMap.getLibrary(dartUri);
 
   /**
    * Return the [PackageBundle] for this SDK, if it exists, or `null` otherwise.
    * This method should not be used outside of `analyzer` and `analyzer_cli`
    * packages.
    */
@@ skipping 101 matching lines @@
   @override
   // TODO(danrubel) Determine SDK version
   String get sdkVersion => '0';
 
   /**
    * The url mappings for this SDK.
    */
   Map<String, String> get urlMappings => _urlMappings;
 
   @override
+  PackageBundle getLinkedBundle() => null;
+
+  @override
   String getRelativePathFromFile(File file) => file.path;
 
   @override
   PackageBundle getSummarySdkBundle(bool strongMode) => null;
 
   @override
   Source internalMapDartUri(String dartUri) {
     String libraryName;
     String relativePath;
     int index = dartUri.indexOf('/');
@@ skipping 425 matching lines @@
     SdkLibrariesReader_LibraryBuilder libraryBuilder =
         new SdkLibrariesReader_LibraryBuilder(_useDart2jsPaths);
     // If any syntactic errors were found then don't try to visit the AST
     // structure.
     if (!errorListener.errorReported) {
       unit.accept(libraryBuilder);
     }
     return libraryBuilder.librariesMap;
   }
 }