Add AnalysisCache.onResultInvalidated, use in DartWorkManager.

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

Index: pkg/analyzer/lib/src/task/dart_work_manager.dart
diff --git a/pkg/analyzer/lib/src/task/dart_work_manager.dart b/pkg/analyzer/lib/src/task/dart_work_manager.dart
index 6e7ba5b50ad74a02732252d74f1254861d8f1cdc..fab0ed11d86a48e83e098fc194afa88d52dab0be 100644
--- a/pkg/analyzer/lib/src/task/dart_work_manager.dart
+++ b/pkg/analyzer/lib/src/task/dart_work_manager.dart
@@ -83,7 +83,16 @@ class DartWorkManager implements WorkManager {
   /**
    * Initialize a newly created manager.
    */
-  DartWorkManager(this.context);
+  DartWorkManager(this.context) {
+    analysisCache.onResultInvalidated.listen((InvalidatedResult event) {
+      if (event.descriptor == LIBRARY_ERRORS_READY) {
+        CacheEntry entry = event.entry;
+        if (entry.getValue(SOURCE_KIND) == SourceKind.LIBRARY) {
+          librarySourceQueue.add(entry.target);
+        }
+      }
+    });
+  }
 
   /**
    * Returns the correctly typed result of `context.analysisCache`.
@@ -128,21 +137,6 @@ class DartWorkManager implements WorkManager {
       partLibrariesMap.remove(removedSource);
       _onLibrarySourceChangedOrRemoved(removedSource);
     }
-    // Some of the libraries might have been invalidated, reschedule them.
-    {
-      MapIterator<AnalysisTarget, CacheEntry> iterator =
-          analysisCache.iterator();
-      while (iterator.moveNext()) {
-        AnalysisTarget target = iterator.key;
-        if (_isDartSource(target)) {
-          CacheEntry entry = iterator.value;
-          if (entry.getValue(SOURCE_KIND) == SourceKind.LIBRARY &&
-              entry.getValue(LIBRARY_ERRORS_READY) != true) {
-            librarySourceQueue.add(target);
-          }
-        }
-      }
-    }
   }
 
   @override