Remove backends.

compiler/java/com/google/dart/compiler/backend/js/ast/JsObjectLiteral.java

-// Copyright (c) 2011, 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.
-
-package com.google.dart.compiler.backend.js.ast;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * A JavaScript object literal.
- */
-public final class JsObjectLiteral extends JsLiteral {
-
-  private final List<JsPropertyInitializer> props = new ArrayList<JsPropertyInitializer>();
-
-  public JsObjectLiteral() {
-  }
-
-  public List<JsPropertyInitializer> getPropertyInitializers() {
-    return props;
-  }
-
-  @Override
-  public boolean hasSideEffects() {
-    for (JsPropertyInitializer prop : props) {
-      if (prop.hasSideEffects()) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  @Override
-  public boolean isBooleanFalse() {
-    return false;
-  }
-
-  @Override
-  public boolean isBooleanTrue() {
-    return true;
-  }
-
-  @Override
-  public boolean isDefinitelyNotNull() {
-    return true;
-  }
-
-  @Override
-  public boolean isDefinitelyNull() {
-    return false;
-  }
-
-  @Override
-  public void traverse(JsVisitor v, JsContext ctx) {
-    if (v.visit(this, ctx)) {
-      v.acceptWithInsertRemove(props);
-    }
-    v.endVisit(this, ctx);
-  }
-
-  @Override
-  public NodeKind getKind() {
-    return NodeKind.OBJECT;
-  }
-}