Remove memento.

pkg/analyzer/lib/src/context/cache.dart

Index: pkg/analyzer/lib/src/context/cache.dart
diff --git a/pkg/analyzer/lib/src/context/cache.dart b/pkg/analyzer/lib/src/context/cache.dart
index c9b9841b8d8648d0a5089a03602edbfc4e2d450a..6785a714e6a99868639063ae61c2addcceade794 100644
--- a/pkg/analyzer/lib/src/context/cache.dart
+++ b/pkg/analyzer/lib/src/context/cache.dart
@@ -259,17 +259,6 @@ class CacheEntry {
   }
 
   /**
-   * Return the memento of the result represented by the given [descriptor].
-   */
-  Object getMemento(ResultDescriptor descriptor) {
-    ResultData data = _resultMap[descriptor];
-    if (data == null) {
-      return null;
-    }
-    return data.memento;
-  }
-
-  /**
    * Return the state of the result represented by the given [descriptor].
    */
   CacheState getState(ResultDescriptor descriptor) {
@@ -380,11 +369,10 @@ class CacheEntry {
 
   /**
    * Set the value of the result represented by the given [descriptor] to the
-   * given [value]. The optional [memento] may help to recompute [value] more
-   * efficiently after invalidation.
+   * given [value].
    */
   /*<V>*/ void setValue(ResultDescriptor /*<V>*/ descriptor, dynamic /*V*/
-      value, List<TargetedResult> dependedOn, Object memento) {
+      value, List<TargetedResult> dependedOn) {
     _validateStateChange(descriptor, CacheState.VALID);
     TargetedResult thisResult = new TargetedResult(target, descriptor);
     if (_partition != null) {
@@ -395,7 +383,6 @@ class CacheEntry {
     _setDependedOnResults(data, thisResult, dependedOn);
     data.state = CacheState.VALID;
     data.value = value == null ? descriptor.defaultValue : value;
-    data.memento = memento;
   }
 
   @override
@@ -788,12 +775,6 @@ class ResultData {
   Object value;
 
   /**
-   * The optional data that is remembered with [value] and, when [value] is
-   * invalidated, may help to recompute it more efficiently.
-   */
-  Object memento;
-
-  /**
    * A list of the results on which this result depends.
    */
   List<TargetedResult> dependedOnResults = <TargetedResult>[];
@@ -818,7 +799,6 @@ class ResultData {
   void flush() {
     state = CacheState.FLUSHED;
     value = descriptor.defaultValue;
-    memento = null;
   }
 }