Remove backends.

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

Index: compiler/java/com/google/dart/compiler/backend/js/ast/JsModVisitor.java
diff --git a/compiler/java/com/google/dart/compiler/backend/js/ast/JsModVisitor.java b/compiler/java/com/google/dart/compiler/backend/js/ast/JsModVisitor.java
deleted file mode 100644
index ef6e75ce994462273ce56ab05b88f947d7d458ce..0000000000000000000000000000000000000000
--- a/compiler/java/com/google/dart/compiler/backend/js/ast/JsModVisitor.java
+++ /dev/null
@@ -1,189 +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;
-
-import com.google.dart.compiler.util.Hack;
-
-import java.util.List;
-
-/**
- * A visitor for iterating through and modifying an AST.
- */
-public class JsModVisitor extends JsVisitor {
-
-  private class ListContext<T extends JsVisitable> implements JsContext {
-
-    private List<T> collection;
-    private int index;
-    private boolean removed;
-    private boolean replaced;
-
-    @Override
-    public boolean canInsert() {
-      return true;
-    }
-
-    @Override
-    public boolean canRemove() {
-      return true;
-    }
-
-    @Override
-    public void insertAfter(JsVisitable node) {
-      checkRemoved();
-      collection.add(index + 1, Hack.<T>cast(node));
-      didChange = true;
-    }
-
-    @Override
-    public void insertBefore(JsVisitable node) {
-      checkRemoved();
-      collection.add(index++, Hack.<T>cast(node));
-      didChange = true;
-    }
-
-    @Override
-    public boolean isLvalue() {
-      return false;
-    }
-
-    @Override
-    public void removeMe() {
-      checkState();
-      collection.remove(index--);
-      didChange = removed = true;
-    }
-
-    @Override
-    public void replaceMe(JsVisitable node) {
-      checkState();
-      checkReplacement(collection.get(index), node);
-      collection.set(index, Hack.<T>cast(node));
-      didChange = replaced = true;
-    }
-
-    protected void traverse(List<T> collection) {
-      this.collection = collection;
-      for (index = 0; index < collection.size(); ++index) {
-        removed = replaced = false;
-        doTraverse(collection.get(index), this);
-      }
-    }
-
-    private void checkRemoved() {
-      if (removed) {
-        throw new RuntimeException("Node was already removed");
-      }
-    }
-
-    private void checkState() {
-      checkRemoved();
-      if (replaced) {
-        throw new RuntimeException("Node was already replaced");
-      }
-    }
-  }
-
-  private class LvalueContext extends NodeContext<JsExpression> {
-    @Override
-    public boolean isLvalue() {
-      return true;
-    }
-  }
-
-  private class NodeContext<T extends JsVisitable> implements JsContext {
-    private T node;
-    private boolean replaced;
-
-    @Override
-    public boolean canInsert() {
-      return false;
-    }
-
-    @Override
-    public boolean canRemove() {
-      return false;
-    }
-
-    @Override
-    public void insertAfter(JsVisitable node) {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public void insertBefore(JsVisitable node) {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public boolean isLvalue() {
-      return false;
-    }
-
-    @Override
-    public void removeMe() {
-      throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public void replaceMe(JsVisitable node) {
-      if (replaced) {
-        throw new RuntimeException("Node was already replaced");
-      }
-      checkReplacement(this.node, node);
-      this.node = Hack.<T>cast(node);
-      didChange = replaced = true;
-    }
-
-    protected T traverse(T node) {
-      this.node = node;
-      replaced = false;
-      doTraverse(node, this);
-      return this.node;
-    }
-  }
-
-  protected static <T extends JsVisitable> void checkReplacement(T origNode, T newNode) {
-    if (newNode == null) {
-      throw new RuntimeException("Cannot replace with null");
-    }
-    if (newNode == origNode) {
-      throw new RuntimeException("The replacement is the same as the original");
-    }
-  }
-
-  protected boolean didChange = false;
-
-  @Override
-  public boolean didChange() {
-    return didChange;
-  }
-
-  @Override
-  protected <T extends JsVisitable> T doAccept(T node) {
-    return new NodeContext<T>().traverse(node);
-  }
-
-  @Override
-  protected <T extends JsVisitable> void doAcceptList(List<T> collection) {
-    NodeContext<T> ctx = new NodeContext<T>();
-    for (int i = 0, c = collection.size(); i < c; ++i) {
-      ctx.traverse(collection.get(i));
-      if (ctx.replaced) {
-        collection.set(i, ctx.node);
-      }
-    }
-  }
-
-  @Override
-  protected JsExpression doAcceptLvalue(JsExpression expr) {
-    return new LvalueContext().traverse(expr);
-  }
-
-  @Override
-  protected <T extends JsVisitable> void doAcceptWithInsertRemove(List<T> collection) {
-    new ListContext<T>().traverse(collection);
-  }
-}