Remove only local variables/functions from the cache.

pkg/analyzer/lib/src/generated/incremental_resolver.dart

Index: pkg/analyzer/lib/src/generated/incremental_resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/incremental_resolver.dart b/pkg/analyzer/lib/src/generated/incremental_resolver.dart
index b19b4b1d06a1ecbe2be76d1046a5f8b933b6a55b..640a58f0042b1927792579ce9eb76f3232d94959 100644
--- a/pkg/analyzer/lib/src/generated/incremental_resolver.dart
+++ b/pkg/analyzer/lib/src/generated/incremental_resolver.dart
@@ -2049,9 +2049,9 @@ class _DeclarationMismatchException {}
 /**
  * Adjusts the location of each Element that moved.
  *
- * Since operator== and hashCode of an Element are based
- * on the element location, we also need to remove each
- * moved element from the cache to avoid a memory leak.
+ * Since `==` and `hashCode` of a local variable or function Element are based
+ * on the element name offsets, we also need to remove these elements from the
+ * cache to avoid a memory leak. TODO(scheglov) fix and remove this
  */
 class _ElementOffsetUpdater extends GeneralizingElementVisitor {
   final int updateOffset;
@@ -2065,7 +2065,13 @@ class _ElementOffsetUpdater extends GeneralizingElementVisitor {
     // name offset
     int nameOffset = element.nameOffset;
     if (nameOffset > updateOffset) {
-      cache.remove(element);
+      // TODO(scheglov) make sure that we don't put local variables
+      // and functions into the cache at all.
+      if (element is LocalVariableElement ||

[skybrian, 2016/02/13 18:39:22]

This check is missing DefaultParameterElementImpl and ConstFieldElementImpl (at
least).

It looks like changing LocalVariableElement to LocalElement might cover it.

But it seems like this check should be reversed. If there are Elements that we
know are safe to move while still in the cache, we can check for those cases and
skip cache.remove(). If we haven't thought about a particular case then we
should default to removing them from the cache, which is always safe but might
be unnecessary.

+          element is FunctionElement &&
+              element.enclosingElement is ExecutableElement) {
+        cache.remove(element);
+      }
       (element as ElementImpl).nameOffset = nameOffset + updateDelta;
       if (element is ConstVariableElement) {
         ConstVariableElement constVariable = element as ConstVariableElement;