Remove unused API.

dart/sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

 // Copyright (c) 2012, 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.
 
 part of js_backend;
 
 const VERBOSE_OPTIMIZER_HINTS = false;
 
 class JavaScriptItemCompilationContext extends ItemCompilationContext {
   final Set<HInstruction> boundsChecked = new Set<HInstruction>();
@@ skipping 956 matching lines @@
     if (element.isTypedef()) {
       typedefTypeLiterals.add(element);
     }
     customElementsAnalysis.registerTypeLiteral(element, enqueuer);
   }
 
   void registerStackTraceInCatch(TreeElements elements) {
     enqueueInResolution(getTraceFromException(), elements);
   }
 
-  void registerSetRuntimeType(TreeElements elements) {
-    enqueueInResolution(getSetRuntimeTypeInfo(), elements);
-  }
-
   void registerGetRuntimeTypeArgument(TreeElements elements) {
     enqueueInResolution(getGetRuntimeTypeArgument(), elements);
     enqueueInResolution(getGetTypeArgumentByIndex(), elements);
     enqueueInResolution(getCopyTypeArguments(), elements);
   }
 
   void registerGenericCallMethod(Element callMethod,
                                  Enqueuer enqueuer, TreeElements elements) {
     if (enqueuer.isResolutionQueue || methodNeedsRti(callMethod)) {
       registerComputeSignature(enqueuer, elements);
@@ skipping 1005 matching lines @@
     copy(constant.values);
     copy(constant.protoValue);
     copy(constant);
   }
 
   void visitConstructed(ConstructedConstant constant) {
     copy(constant.fields);
     copy(constant);
   }
 }