Issue 24538. Route SDK results into SDK context DartWorkManager.

pkg/analyzer/test/src/context/context_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.src.context.context_test;
 
 import 'dart:async';
 
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/cancelable_future.dart';
@@ skipping 1173 matching lines @@
     sources = context.librarySources;
     expect(sources, hasLength(originalLength + 1));
     for (Source returnedSource in sources) {
       if (returnedSource == source) {
         return;
       }
     }
     fail("The added source was not in the list of library sources");
   }
 
+  void test_getLibrarySources_inSDK() {
+    Source source = addSource(
+        '/test.dart',
+        r'''
+import 'dart:async';
+Stream S = null;
+''');
+    LibraryElement testLibrary = context.computeLibraryElement(source);
+    // prepare "Stream" ClassElement
+    ClassElement streamElement;
+    {
+      CompilationUnitElement testUnit = testLibrary.definingCompilationUnit;
+      InterfaceType streamType = testUnit.topLevelVariables[0].type;
+      streamElement = streamType.element;
+    }
+    // must be from SDK context
+    AnalysisContext sdkContext = context.sourceFactory.dartSdk.context;
+    expect(sdkContext, streamElement.context);
+    // must be in the "async" library
+    Source intSource = streamElement.source;
+    List<Source> coreLibraries = sdkContext.getLibrariesContaining(intSource);
+    expect(coreLibraries, hasLength(1));
+    Source coreSource = coreLibraries[0];
+    expect(coreSource.isInSystemLibrary, isTrue);
+    expect(coreSource.shortName, 'async.dart');
+  }
+
   void test_getLineInfo() {
     Source source = addSource(
         "/test.dart",
         r'''
 library lib;
 
 main() {}''');
     LineInfo info = context.getLineInfo(source);
     expect(info, isNull);
     context.parseCompilationUnit(source);
@@ skipping 1311 matching lines @@
   }
 }
 
 class _AnalysisContextImplTest_test_applyChanges_removeContainer
     implements SourceContainer {
   Source libB;
   _AnalysisContextImplTest_test_applyChanges_removeContainer(this.libB);
   @override
   bool contains(Source source) => source == libB;
 }