Change NestedGraphLens to inherit from DefaultNonIdentityGraphLens

Change-Id: I6184fbb25a05aa490dd23088f889e6681097edcb
diff --git a/src/main/java/com/android/tools/r8/graph/lens/NestedGraphLens.java b/src/main/java/com/android/tools/r8/graph/lens/NestedGraphLens.java
index ee3efbe..694425b 100644
--- a/src/main/java/com/android/tools/r8/graph/lens/NestedGraphLens.java
+++ b/src/main/java/com/android/tools/r8/graph/lens/NestedGraphLens.java
@@ -31,7 +31,7 @@
  * #mapInvocationType(DexMethod, DexMethod, InvokeType)} if the default name mapping applies, and
  * only invocation type might need to change.
  */
-public class NestedGraphLens extends NonIdentityGraphLens {
+public class NestedGraphLens extends DefaultNonIdentityGraphLens {
 
   protected static final EmptyBidirectionalOneToOneMap<DexField, DexField> EMPTY_FIELD_MAP =
       new EmptyBidirectionalOneToOneMap<>();
@@ -307,14 +307,6 @@
   }
 
   @Override
-  public boolean isContextFreeForMethods(GraphLens codeLens) {
-    if (codeLens == this) {
-      return true;
-    }
-    return getPrevious().isContextFreeForMethods(codeLens);
-  }
-
-  @Override
   public boolean verifyIsContextFreeForMethod(DexMethod method, GraphLens codeLens) {
     assert codeLens == this
         || getPrevious().verifyIsContextFreeForMethod(getPreviousMethodSignature(method), codeLens);