Address comments from CL 739513002.

dart/pkg/dart2js_incremental/lib/library_updater.dart

Index: dart/pkg/dart2js_incremental/lib/library_updater.dart
diff --git a/dart/pkg/dart2js_incremental/lib/library_updater.dart b/dart/pkg/dart2js_incremental/lib/library_updater.dart
index c9ce69a368ec4d58cd1959d44a44b6d4f9753748..cc29d1b9c3c7157947f2dba25035bad48e86f2fa 100644
--- a/dart/pkg/dart2js_incremental/lib/library_updater.dart
+++ b/dart/pkg/dart2js_incremental/lib/library_updater.dart
@@ -606,11 +606,12 @@ class LibraryUpdater extends JsFeatures {
       statements.add(
           js.statement('#.prototype.# = f', [elementAccess, name]));
 
-      if (backend.isAliasedSuperMember(element)) {
-        String superName = namer.getNameOfAliasedSuperMember(element);
-        statements.add(
-            js.statement('#.prototype.# = f', [elementAccess, superName]));
-      }
+      // TODO(ahe): Restore when isAliasedSuperMember is restored.
+      // if (backend.isAliasedSuperMember(element)) {
+      //   String superName = namer.getNameOfAliasedSuperMember(element);
+      //   statements.add(
+      //       js.statement('#.prototype.# = f', [elementAccess, superName]));
+      // }
     } else {
       jsAst.Node elementAccess = namer.elementAccess(element);
       jsAst.Expression globalFunctionsAccess =
@@ -790,9 +791,10 @@ class RemovedFunctionUpdate extends RemovalUpdate
     if (element.isInstanceMember) {
       elementAccess = namer.elementAccess(element.enclosingClass);
       name = namer.getNameOfMember(element);
-      if (backend.isAliasedSuperMember(element)) {
-        superName = namer.getNameOfAliasedSuperMember(element);
-      }
+      // TODO(ahe): Restore when isAliasedSuperMember is restored.
+      // if (backend.isAliasedSuperMember(element)) {
+      //   superName = namer.getNameOfAliasedSuperMember(element);
+      // }
     } else {
       elementAccess = namer.elementAccess(element);
     }
@@ -841,8 +843,6 @@ class RemovedClassUpdate extends RemovalUpdate with JsFeatures {
 
   PartialClassElement get after => null;
 
-  bool get isRemoval => true;
-
   void captureState() {
     if (wasStateCaptured) throw "captureState was called twice.";
     wasStateCaptured = true;