Remove backends.

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

Index: compiler/java/com/google/dart/compiler/backend/js/ast/JsOperator.java
diff --git a/compiler/java/com/google/dart/compiler/backend/js/ast/JsOperator.java b/compiler/java/com/google/dart/compiler/backend/js/ast/JsOperator.java
deleted file mode 100644
index e4440cbe9abdadb6db8c0d9ba2e8a5c24a23f0d5..0000000000000000000000000000000000000000
--- a/compiler/java/com/google/dart/compiler/backend/js/ast/JsOperator.java
+++ /dev/null
@@ -1,32 +0,0 @@
-// 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;
-
-/**
- * A JavaScript operator.
- */
-public interface JsOperator {
-
-  int INFIX = 0x02;
-  int LEFT = 0x01;
-  int POSTFIX = 0x04;
-  int PREFIX = 0x08;
-
-  int getPrecedence();
-
-  String getSymbol();
-
-  boolean isKeyword();
-
-  boolean isLeftAssociative();
-
-  boolean isPrecedenceLessThan(JsOperator other);
-
-  boolean isValidInfix();
-
-  boolean isValidPostfix();
-
-  boolean isValidPrefix();
-}