Share LibrarySpecificUnits when possible

pkg/analyzer/lib/src/task/dart.dart

 // Copyright (c) 2015, 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.task.dart;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 4064 matching lines @@
     List<Source> exportedSources = exportedSourceSet.toList();
     List<Source> importedSources = importedSourceSet.toList();
     List<Source> includedSources = includedSourceSet.toList();
     List<AnalysisError> parseErrors = getUniqueErrors(errorListener.errors);
     List<Source> unitSources = <Source>[source]..addAll(includedSourceSet);
     List<Source> referencedSources = (new Set<Source>()
           ..addAll(importedSources)
           ..addAll(exportedSources)
           ..addAll(unitSources))
         .toList();
-    List<LibrarySpecificUnit> librarySpecificUnits =
-        unitSources.map((s) => new LibrarySpecificUnit(source, s)).toList();
+    List<LibrarySpecificUnit> librarySpecificUnits = unitSources
+        .map((s) => (context as InternalAnalysisContext)
+            .getLibrarySpecificUnit(source, s))
+        .toList();
     outputs[EXPLICITLY_IMPORTED_LIBRARIES] = explicitlyImportedSources;
     outputs[EXPORTED_LIBRARIES] = exportedSources;
     outputs[IMPORTED_LIBRARIES] = importedSources;
     outputs[INCLUDED_PARTS] = includedSources;
     outputs[LIBRARY_SPECIFIC_UNITS] = librarySpecificUnits;
     outputs[PARSE_ERRORS] = parseErrors;
     outputs[PARSED_UNIT] = unit;
     outputs[REFERENCED_NAMES] = referencedNames;
     outputs[REFERENCED_SOURCES] = referencedSources;
     outputs[SOURCE_KIND] = sourceKind;
@@ skipping 2374 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }