Add AnalysisDriver.onResultComputed().

pkg/analyzer/lib/src/context/context.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.context.context;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/instrumentation/instrumentation.dart';
@@ skipping 1895 matching lines @@
       _completer.completeError(exception, stackTrace);
     }
   }
 
   void _onCancel() {
     _context._cancelFuture(this);
   }
 }
 
 /**
+ * [ResultComputedEvent] describes a value computed for a [ResultDescriptor].
+ */
+class ResultComputedEvent<V> {
+  /**
+   * The context in which the value was computed.
+   */
+  final AnalysisContext context;
+
+  /**
+   * The descriptor of the result which was computed.
+   */
+  final ResultDescriptor<V> descriptor;
+
+  /**
+   * The target for which the result was computed.
+   */
+  final AnalysisTarget target;
+
+  /**
+   * The computed value.
+   */
+  final V value;
+
+  ResultComputedEvent(this.context, this.descriptor, this.target, this.value);
+
+  @override
+  String toString() => '$value for $descriptor of $target in $context';
+}
+
+/**
  * An [AnalysisContext] that only contains sources for a Dart SDK.
  */
 class SdkAnalysisContext extends AnalysisContextImpl {
   @override
   AnalysisCache createCacheFromSourceFactory(SourceFactory factory) {
     if (factory == null) {
       return super.createCacheFromSourceFactory(factory);
     }
     DartSdk sdk = factory.dartSdk;
     if (sdk == null) {
@@ skipping 45 matching lines @@
     PendingFuture pendingFuture =
         new PendingFuture<T>(_context, target, computeValue);
     if (!pendingFuture.evaluate(entry)) {
       _context._pendingFutureTargets
           .putIfAbsent(target, () => <PendingFuture>[])
           .add(pendingFuture);
     }
     return pendingFuture.future;
   }
 }