Revert "Removed Dartium SDK libs"

sdk/lib/js/dartium/js_dartium.dart

+// Copyright (c) 2013, 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.
+
+/**
+ * Support for interoperating with JavaScript.
+ *
+ * This library provides access to JavaScript objects from Dart, allowing
+ * Dart code to get and set properties, and call methods of JavaScript objects
+ * and invoke JavaScript functions. The library takes care of converting
+ * between Dart and JavaScript objects where possible, or providing proxies if
+ * conversion isn't possible.
+ *
+ * This library does not yet make Dart objects usable from JavaScript, their
+ * methods and proeprties are not accessible, though it does allow Dart
+ * functions to be passed into and called from JavaScript.
+ *
+ * [JsObject] is the core type and represents a proxy of a JavaScript object.
+ * JsObject gives access to the underlying JavaScript objects properties and
+ * methods. `JsObject`s can be acquired by calls to JavaScript, or they can be
+ * created from proxies to JavaScript constructors.
+ *
+ * The top-level getter [context] provides a [JsObject] that represents the
+ * global object in JavaScript, usually `window`.
+ *
+ * The following example shows an alert dialog via a JavaScript call to the
+ * global function `alert()`:
+ *
+ *     import 'dart:js';
+ *
+ *     main() => context.callMethod('alert', ['Hello from Dart!']);
+ *
+ * This example shows how to create a [JsObject] from a JavaScript constructor
+ * and access its properties:
+ *
+ *     import 'dart:js';
+ *
+ *     main() {
+ *       var object = new JsObject(context['Object']);
+ *       object['greeting'] = 'Hello';
+ *       object['greet'] = (name) => "${object['greeting']} $name";
+ *       var message = object.callMethod('greet', ['JavaScript']);
+ *       context['console'].callMethod('log', [message]);
+ *     }
+ *
+ * ## Proxying and automatic conversion
+ *
+ * When setting properties on a JsObject or passing arguments to a Javascript
+ * method or function, Dart objects are automatically converted or proxied to
+ * JavaScript objects. When accessing JavaScript properties, or when a Dart
+ * closure is invoked from JavaScript, the JavaScript objects are also
+ * converted to Dart.
+ *
+ * Functions and closures are proxied in such a way that they are callable. A
+ * Dart closure assigned to a JavaScript property is proxied by a function in
+ * JavaScript. A JavaScript function accessed from Dart is proxied by a
+ * [JsFunction], which has a [apply] method to invoke it.
+ *
+ * The following types are transferred directly and not proxied:
+ *
+ * * "Basic" types: `null`, `bool`, `num`, `String`, `DateTime`
+ * * `Blob`
+ * * `Event`
+ * * `HtmlCollection`
+ * * `ImageData`
+ * * `KeyRange`
+ * * `Node`
+ * * `NodeList`
+ * * `TypedData`, including its subclasses like `Int32List`, but _not_
+ *   `ByteBuffer`
+ * * `Window`
+ *
+ * ## Converting collections with JsObject.jsify()
+ *
+ * To create a JavaScript collection from a Dart collection use the
+ * [JsObject.jsify] constructor, which converts Dart [Map]s and [Iterable]s
+ * into JavaScript Objects and Arrays.
+ *
+ * The following expression creates a new JavaScript object with the properties
+ * `a` and `b` defined:
+ *
+ *     var jsMap = new JsObject.jsify({'a': 1, 'b': 2});
+ *
+ * This expression creates a JavaScript array:
+ *
+ *     var jsArray = new JsObject.jsify([1, 2, 3]);
+ */
+library dart.js;
+
+import 'dart:collection' show ListMixin;
+import 'dart:nativewrappers';
+import 'dart:math' as math;
+import 'dart:mirrors' as mirrors;
+import 'dart:html' as html;
+import 'dart:_blink' as _blink;
+import 'dart:html_common' as html_common;
+import 'dart:indexed_db' as indexed_db;
+import 'dart:typed_data';
+import 'dart:core';
+
+import 'cached_patches.dart';
+
+// Pretend we are always in checked mode as we aren't interested in users
+// running Dartium code outside of checked mode.
+@Deprecated("Internal Use Only")
+final bool CHECK_JS_INVOCATIONS = true;
+
+final String _DART_RESERVED_NAME_PREFIX = r'JS$';
+// If a private class is defined to use @JS we need to inject a non-private
+// class with a name that will not cause collisions in the library so we can
+// make JSObject implement that interface even though it is in a different
+// library.
+final String escapePrivateClassPrefix = r'$JSImplClass23402893498';
+
+// Exposed to return ArrayBufferView from a TypedArray passed to readPixels.
+toArrayBufferView(TypedData data) native "Dart_TypedArray_ArrayBufferView";
+
+String _stripReservedNamePrefix(String name) =>
+    name.startsWith(_DART_RESERVED_NAME_PREFIX)
+        ? name.substring(_DART_RESERVED_NAME_PREFIX.length)
+        : name;
+
+_buildArgs(Invocation invocation) {
+  if (invocation.namedArguments.isEmpty) {
+    return invocation.positionalArguments;
+  } else {
+    var varArgs = new Map<String, Object>();
+    invocation.namedArguments.forEach((symbol, val) {
+      varArgs[mirrors.MirrorSystem.getName(symbol)] = val;
+    });
+    return invocation.positionalArguments.toList()
+      ..add(JsNative.jsify(varArgs));
+  }
+}
+
+final _allowedMethods = new Map<Symbol, _DeclarationSet>();
+final _allowedGetters = new Map<Symbol, _DeclarationSet>();
+final _allowedSetters = new Map<Symbol, _DeclarationSet>();
+
+final _jsInterfaceTypes = new Set<mirrors.ClassMirror>();
+@Deprecated("Internal Use Only")
+Iterable<mirrors.ClassMirror> get jsInterfaceTypes => _jsInterfaceTypes;
+
+class _StringLiteralEscape {
+  // Character code constants.
+  static const int BACKSPACE = 0x08;
+  static const int TAB = 0x09;
+  static const int NEWLINE = 0x0a;
+  static const int CARRIAGE_RETURN = 0x0d;
+  static const int FORM_FEED = 0x0c;
+  static const int QUOTE = 0x22;
+  static const int CHAR_$ = 0x24;
+  static const int CHAR_0 = 0x30;
+  static const int BACKSLASH = 0x5c;
+  static const int CHAR_b = 0x62;
+  static const int CHAR_f = 0x66;
+  static const int CHAR_n = 0x6e;
+  static const int CHAR_r = 0x72;
+  static const int CHAR_t = 0x74;
+  static const int CHAR_u = 0x75;
+
+  final StringSink _sink;
+
+  _StringLiteralEscape(this._sink);
+
+  void writeString(String string) {
+    _sink.write(string);
+  }
+
+  void writeStringSlice(String string, int start, int end) {
+    _sink.write(string.substring(start, end));
+  }
+
+  void writeCharCode(int charCode) {
+    _sink.writeCharCode(charCode);
+  }
+
+  /// ('0' + x) or ('a' + x - 10)
+  static int hexDigit(int x) => x < 10 ? 48 + x : 87 + x;
+
+  /// Write, and suitably escape, a string's content as a JSON string literal.
+  void writeStringContent(String s) {
+    // Identical to JSON string literal escaping except that we also escape $.
+    int offset = 0;
+    final int length = s.length;
+    for (int i = 0; i < length; i++) {
+      int charCode = s.codeUnitAt(i);
+      if (charCode > BACKSLASH) continue;
+      if (charCode < 32) {
+        if (i > offset) writeStringSlice(s, offset, i);
+        offset = i + 1;
+        writeCharCode(BACKSLASH);
+        switch (charCode) {
+          case BACKSPACE:
+            writeCharCode(CHAR_b);
+            break;
+          case TAB:
+            writeCharCode(CHAR_t);
+            break;
+          case NEWLINE:
+            writeCharCode(CHAR_n);
+            break;
+          case FORM_FEED:
+            writeCharCode(CHAR_f);
+            break;
+          case CARRIAGE_RETURN:
+            writeCharCode(CHAR_r);
+            break;
+          default:
+            writeCharCode(CHAR_u);
+            writeCharCode(CHAR_0);
+            writeCharCode(CHAR_0);
+            writeCharCode(hexDigit((charCode >> 4) & 0xf));
+            writeCharCode(hexDigit(charCode & 0xf));
+            break;
+        }
+      } else if (charCode == QUOTE ||
+          charCode == BACKSLASH ||
+          charCode == CHAR_$) {
+        if (i > offset) writeStringSlice(s, offset, i);
+        offset = i + 1;
+        writeCharCode(BACKSLASH);
+        writeCharCode(charCode);
+      }
+    }
+    if (offset == 0) {
+      writeString(s);
+    } else if (offset < length) {
+      writeStringSlice(s, offset, length);
+    }
+  }
+
+  /**
+   * Serialize a [num], [String], [bool], [Null], [List] or [Map] value.
+   *
+   * Returns true if the value is one of these types, and false if not.
+   * If a value is both a [List] and a [Map], it's serialized as a [List].
+   */
+  bool writeStringLiteral(String str) {
+    writeString('"');
+    writeStringContent(str);
+    writeString('"');
+  }
+}
+
+String _escapeString(String str) {
+  StringBuffer output = new StringBuffer();
+  new _StringLiteralEscape(output)..writeStringLiteral(str);
+  return output.toString();
+}
+
+/// A collection of methods where all methods have the same name.
+/// This class is intended to optimize whether a specific invocation is
+/// appropriate for at least some of the methods in the collection.
+class _DeclarationSet {
+  _DeclarationSet() : _members = <mirrors.DeclarationMirror>[];
+
+  static bool _checkType(obj, mirrors.TypeMirror type) {
+    if (obj == null) return true;
+    return mirrors.reflectType(obj.runtimeType).isSubtypeOf(type);
+  }
+
+  /// Returns whether the return [value] has a type is consistent with the
+  /// return type from at least one of the members matching the DeclarationSet.
+  bool _checkReturnType(value) {
+    if (value == null) return true;
+    var valueMirror = mirrors.reflectType(value.runtimeType);
+    for (var member in _members) {
+      if (member is mirrors.VariableMirror || member.isGetter) {
+        // TODO(jacobr): actually check return types for getters that return
+        // function types.
+        return true;
+      } else {
+        if (valueMirror.isSubtypeOf(member.returnType)) return true;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Check whether the [invocation] is consistent with the [member] mirror.
+   */
+  bool _checkDeclaration(
+      Invocation invocation, mirrors.DeclarationMirror member) {
+    if (member is mirrors.VariableMirror || (member as dynamic).isGetter) {
+      // TODO(jacobr): actually check method types against the function type
+      // returned by the getter or field.
+      return true;
+    }
+    var parameters = (member as dynamic).parameters;
+    var positionalArguments = invocation.positionalArguments;
+    // Too many arguments
+    if (parameters.length < positionalArguments.length) return false;
+    // Too few required arguments.
+    if (parameters.length > positionalArguments.length &&
+        !parameters[positionalArguments.length].isOptional) return false;
+    for (var i = 0; i < positionalArguments.length; i++) {
+      if (parameters[i].isNamed) {
+        // Not enough positional arguments.
+        return false;
+      }
+      if (!_checkType(invocation.positionalArguments[i], parameters[i].type))
+        return false;
+    }
+    if (invocation.namedArguments.isNotEmpty) {
+      var startNamed;
+      for (startNamed = parameters.length - 1; startNamed >= 0; startNamed--) {
+        if (!parameters[startNamed].isNamed) break;
+      }
+      startNamed++;
+
+      // TODO(jacobr): we are unnecessarily using an O(n^2) algorithm here.
+      // If we have JS APIs with a large number of named parameters we should
+      // optimize this. Either use a HashSet or invert this, walking over
+      // parameters, querying invocation, and making sure we match
+      //invocation.namedArguments.size keys.
+      for (var name in invocation.namedArguments.keys) {
+        bool match = false;
+        for (var j = startNamed; j < parameters.length; j++) {
+          var p = parameters[j];
+          if (p.simpleName == name) {
+            if (!_checkType(
+                invocation.namedArguments[name], parameters[j].type))
+              return false;
+            match = true;
+            break;
+          }
+        }
+        if (match == false) return false;
+      }
+    }
+    return true;
+  }
+
+  bool checkInvocation(Invocation invocation) {
+    for (var member in _members) {
+      if (_checkDeclaration(invocation, member)) return true;
+    }
+    return false;
+  }
+
+  void add(mirrors.DeclarationMirror mirror) {
+    _members.add(mirror);
+  }
+
+  final List<mirrors.DeclarationMirror> _members;
+}
+
+/**
+ * Temporary method that we hope to remove at some point. This method should
+ * generally only be called by machine generated code.
+ */
+@Deprecated("Internal Use Only")
+void registerJsInterfaces([List<Type> classes]) {
+  // This method is now obsolete in Dartium.
+}
+
+void _registerJsInterfaces(List<Type> classes) {
+  for (Type type in classes) {
+    mirrors.ClassMirror typeMirror = mirrors.reflectType(type);
+    typeMirror.declarations.forEach((symbol, declaration) {
+      if (declaration is mirrors.MethodMirror ||
+          declaration is mirrors.VariableMirror && !declaration.isStatic) {
+        bool treatAsGetter = false;
+        bool treatAsSetter = false;
+        if (declaration is mirrors.VariableMirror) {
+          treatAsGetter = true;
+          if (!declaration.isConst && !declaration.isFinal) {
+            treatAsSetter = true;
+          }
+        } else {
+          if (declaration.isGetter) {
+            treatAsGetter = true;
+          } else if (declaration.isSetter) {
+            treatAsSetter = true;
+          } else if (!declaration.isConstructor) {
+            _allowedMethods
+                .putIfAbsent(symbol, () => new _DeclarationSet())
+                .add(declaration);
+          }
+        }
+        if (treatAsGetter) {
+          _allowedGetters
+              .putIfAbsent(symbol, () => new _DeclarationSet())
+              .add(declaration);
+          _allowedMethods
+              .putIfAbsent(symbol, () => new _DeclarationSet())
+              .add(declaration);
+        }
+        if (treatAsSetter) {
+          _allowedSetters
+              .putIfAbsent(symbol, () => new _DeclarationSet())
+              .add(declaration);
+        }
+      }
+    });
+  }
+}
+
+_finalizeJsInterfaces() native "Js_finalizeJsInterfaces";
+
+String _getJsName(mirrors.DeclarationMirror mirror) {
+  if (_atJsType != null) {
+    for (var annotation in mirror.metadata) {
+      if (annotation.type.reflectedType == _atJsType) {
+        try {
+          var name = annotation.reflectee.name;
+          return name != null ? name : "";
+        } catch (e) {}
+      }
+    }
+  }
+  return null;
+}
+
+bool _isAnonymousClass(mirrors.ClassMirror mirror) {
+  for (var annotation in mirror.metadata) {
+    if (mirrors.MirrorSystem.getName(annotation.type.simpleName) ==
+        "_Anonymous") {
+      mirrors.LibraryMirror library = annotation.type.owner;
+      var uri = library.uri;
+      // make sure the annotation is from package://js
+      if (uri.scheme == 'package' && uri.path == 'js/js.dart') {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+bool _hasJsName(mirrors.DeclarationMirror mirror) {
+  if (_atJsType != null) {
+    for (var annotation in mirror.metadata) {
+      if (annotation.type.reflectedType == _atJsType) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+var _domNameType;
+
+bool hasDomName(mirrors.DeclarationMirror mirror) {
+  var location = mirror.location;
+  if (location == null || location.sourceUri.scheme != 'dart') return false;
+  for (var annotation in mirror.metadata) {
+    if (mirrors.MirrorSystem.getName(annotation.type.simpleName) == "DomName") {
+      // We can't make sure the annotation is in dart: as Dartium believes it
+      // is file://dart/sdk/lib/html/html_common/metadata.dart
+      // instead of a proper dart: location.
+      return true;
+    }
+  }
+  return false;
+}
+
+_getJsMemberName(mirrors.DeclarationMirror mirror) {
+  var name = _getJsName(mirror);
+  return name == null || name.isEmpty
+      ? _stripReservedNamePrefix(_getDeclarationName(mirror))
+      : name;
+}
+
+// TODO(jacobr): handle setters correctyl.
+String _getDeclarationName(mirrors.DeclarationMirror declaration) {
+  var name = mirrors.MirrorSystem.getName(declaration.simpleName);
+  if (declaration is mirrors.MethodMirror && declaration.isSetter) {
+    assert(name.endsWith("="));
+    name = name.substring(0, name.length - 1);
+  }
+  return name;
+}
+
+final _JS_LIBRARY_PREFIX = "js_library";
+final _UNDEFINED_VAR = "_UNDEFINED_JS_CONST";
+
+String _accessJsPath(String path) => _accessJsPathHelper(path.split("."));
+
+String _accessJsPathHelper(Iterable<String> parts) {
+  var sb = new StringBuffer();
+  sb
+    ..write('${_JS_LIBRARY_PREFIX}.JsNative.getProperty(' * parts.length)
+    ..write("${_JS_LIBRARY_PREFIX}.context");
+  for (var p in parts) {
+    sb.write(", ${_escapeString(p)})");
+  }
+  return sb.toString();
+}
+
+// TODO(jacobr): remove these helpers and add JsNative.setPropertyDotted,
+// getPropertyDotted, and callMethodDotted helpers that would be simpler
+// and more efficient.
+String _accessJsPathSetter(String path) {
+  var parts = path.split(".");
+  return "${_JS_LIBRARY_PREFIX}.JsNative.setProperty(${_accessJsPathHelper(parts.getRange(0, parts.length - 1))
+      }, ${_escapeString(parts.last)}, v)";
+}
+
+String _accessJsPathCallMethodHelper(String path) {
+  var parts = path.split(".");
+  return "${_JS_LIBRARY_PREFIX}.JsNative.callMethod(${_accessJsPathHelper(parts.getRange(0, parts.length - 1))
+      }, ${_escapeString(parts.last)},";
+}
+
+@Deprecated("Internal Use Only")
+void addMemberHelper(
+    mirrors.MethodMirror declaration, String path, StringBuffer sb,
+    {bool isStatic: false, String memberName}) {
+  if (!declaration.isConstructor) {
+    var jsName = _getJsMemberName(declaration);
+    path = (path != null && path.isNotEmpty) ? "${path}.${jsName}" : jsName;
+  }
+  var name = memberName != null ? memberName : _getDeclarationName(declaration);
+  if (declaration.isConstructor) {
+    sb.write("factory");
+  } else if (isStatic) {
+    sb.write("static");
+  } else {
+    sb.write("@patch");
+  }
+  sb.write(" ");
+  if (declaration.isGetter) {
+    sb.write("get $name => ${_accessJsPath(path)};");
+  } else if (declaration.isSetter) {
+    sb.write("set $name(v) {\n"
+        "  ${_JS_LIBRARY_PREFIX}.safeForTypedInterop(v);\n"
+        "  return ${_accessJsPathSetter(path)};\n"
+        "}\n");
+  } else {
+    sb.write("$name(");
+    bool hasOptional = false;
+    int i = 0;
+    var args = <String>[];
+    for (var p in declaration.parameters) {
+      assert(!p.isNamed); // TODO(jacobr): throw.
+      assert(!p.hasDefaultValue);
+      if (i > 0) {
+        sb.write(", ");
+      }
+      if (p.isOptional && !hasOptional) {
+        sb.write("[");
+        hasOptional = true;
+      }
+      var arg = "p$i";
+      args.add(arg);
+      sb.write(arg);
+      if (p.isOptional) {
+        sb.write("=${_UNDEFINED_VAR}");
+      }
+      i++;
+    }
+    if (hasOptional) {
+      sb.write("]");
+    }
+    // TODO(jacobr):
+    sb.write(") {\n");
+    for (var arg in args) {
+      sb.write("  ${_JS_LIBRARY_PREFIX}.safeForTypedInterop($arg);\n");
+    }
+    sb.write("  return ");
+    if (declaration.isConstructor) {
+      sb.write("${_JS_LIBRARY_PREFIX}.JsNative.callConstructor(");
+      sb..write(_accessJsPath(path))..write(",");
+    } else {
+      sb.write(_accessJsPathCallMethodHelper(path));
+    }
+    sb.write("[${args.join(",")}]");
+
+    if (hasOptional) {
+      sb.write(".takeWhile((i) => i != ${_UNDEFINED_VAR}).toList()");
+    }
+    sb.write(");");
+    sb.write("}\n");
+  }
+  sb.write("\n");
+}
+
+bool _isExternal(mirrors.MethodMirror mirror) {
+  // This try-catch block is a workaround for BUG:24834.
+  try {
+    return mirror.isExternal;
+  } catch (e) {}
+  return false;
+}
+
+List<String> _generateExternalMethods(
+    List<String> libraryPaths, bool useCachedPatches) {
+  var staticCodegen = <String>[];
+
+  if (libraryPaths.length == 0) {
+    mirrors.currentMirrorSystem().libraries.forEach((uri, library) {
+      var library_name = "${uri.scheme}:${uri.path}";
+      if (useCachedPatches && cached_patches.containsKey(library_name)) {
+        // Use the pre-generated patch files for DOM dart:nnnn libraries.
+        var patch = cached_patches[library_name];
+        staticCodegen.addAll(patch);
+      } else if (_hasJsName(library)) {
+        // Library marked with @JS
+        _generateLibraryCodegen(uri, library, staticCodegen);
+      } else if (!useCachedPatches) {
+        // Can't use the cached patches file, instead this is a signal to generate
+        // the patches for this file.
+        _generateLibraryCodegen(uri, library, staticCodegen);
+      }
+    }); // End of library foreach
+  } else {
+    // Used to generate cached_patches.dart file for all IDL generated dart:
+    // files to the WebKit DOM.
+    for (var library_name in libraryPaths) {
+      var parts = library_name.split(':');
+      var uri = new Uri(scheme: parts[0], path: parts[1]);
+      var library = mirrors.currentMirrorSystem().libraries[uri];
+      _generateLibraryCodegen(uri, library, staticCodegen);
+    }
+  }
+
+  return staticCodegen;
+}
+
+_generateLibraryCodegen(uri, library, staticCodegen) {
+  // Is it a dart generated library?
+  var dartLibrary = uri.scheme == 'dart';
+
+  var sb = new StringBuffer();
+  String jsLibraryName = _getJsName(library);
+
+  // Sort by patch file by its declaration name.
+  var sortedDeclKeys = library.declarations.keys.toList();
+  sortedDeclKeys.sort((a, b) => mirrors.MirrorSystem
+      .getName(a)
+      .compareTo(mirrors.MirrorSystem.getName(b)));
+
+  sortedDeclKeys.forEach((name) {
+    var declaration = library.declarations[name];
+    if (declaration is mirrors.MethodMirror) {
+      if ((_hasJsName(declaration) || jsLibraryName != null) &&
+          _isExternal(declaration)) {
+        addMemberHelper(declaration, jsLibraryName, sb);
+      }
+    } else if (declaration is mirrors.ClassMirror) {
+      mirrors.ClassMirror clazz = declaration;
+      var isDom = dartLibrary ? hasDomName(clazz) : false;
+      var isJsInterop = _hasJsName(clazz);
+      if (isDom || isJsInterop) {
+        // TODO(jacobr): verify class implements JavaScriptObject.
+        var className = mirrors.MirrorSystem.getName(clazz.simpleName);
+        bool isPrivateUserDefinedClass =
+            className.startsWith('_') && !dartLibrary;
+        var classNameImpl = '${className}Impl';
+        var sbPatch = new StringBuffer();
+        if (isJsInterop) {
+          String jsClassName = _getJsMemberName(clazz);
+
+          jsInterfaceTypes.add(clazz);
+          clazz.declarations.forEach((name, declaration) {
+            if (declaration is! mirrors.MethodMirror ||
+                !_isExternal(declaration)) return;
+            if (declaration.isFactoryConstructor && _isAnonymousClass(clazz)) {
+              sbPatch.write("  factory ${className}(");
+              int i = 0;
+              var args = <String>[];
+              for (var p in declaration.parameters) {
+                args.add(mirrors.MirrorSystem.getName(p.simpleName));
+                i++;
+              }
+              if (args.isNotEmpty) {
+                sbPatch
+                  ..write('{')
+                  ..write(
+                      args.map((name) => '$name:${_UNDEFINED_VAR}').join(", "))
+                  ..write('}');
+              }
+              sbPatch.write(") {\n"
+                  "    var ret = ${_JS_LIBRARY_PREFIX}.JsNative.newObject();\n");
+              i = 0;
+              for (var p in declaration.parameters) {
+                assert(p.isNamed); // TODO(jacobr): throw.
+                var name = args[i];
+                var jsName = _stripReservedNamePrefix(
+                    mirrors.MirrorSystem.getName(p.simpleName));
+                sbPatch.write("    if($name != ${_UNDEFINED_VAR}) {\n"
+                    "      ${_JS_LIBRARY_PREFIX}.safeForTypedInterop($name);\n"
+                    "      ${_JS_LIBRARY_PREFIX}.JsNative.setProperty(ret, ${_escapeString(jsName)}, $name);\n"
+                    "    }\n");
+                i++;
+              }
+
+              sbPatch.write("  return ret;"
+                  "}\n");
+            } else if (declaration.isConstructor ||
+                declaration.isFactoryConstructor) {
+              sbPatch.write("  ");
+              addMemberHelper(
+                  declaration,
+                  (jsLibraryName != null && jsLibraryName.isNotEmpty)
+                      ? "${jsLibraryName}.${jsClassName}"
+                      : jsClassName,
+                  sbPatch,
+                  isStatic: true,
+                  memberName: className);
+            }
+          }); // End of clazz.declarations.forEach
+
+          clazz.staticMembers.forEach((memberName, member) {
+            if (_isExternal(member)) {
+              sbPatch.write("  ");
+              addMemberHelper(
+                  member,
+                  (jsLibraryName != null && jsLibraryName.isNotEmpty)
+                      ? "${jsLibraryName}.${jsClassName}"
+                      : jsClassName,
+                  sbPatch,
+                  isStatic: true);
+            }
+          });
+        }
+        if (isDom) {
+          sbPatch.write(
+              "  static Type get instanceRuntimeType => ${classNameImpl};\n");
+        }
+        if (isPrivateUserDefinedClass) {
+          sb.write("""
+class ${escapePrivateClassPrefix}${className} implements $className {}
+""");
+        }
+
+        if (sbPatch.isNotEmpty) {
+          var typeVariablesClause = '';
+          if (!clazz.typeVariables.isEmpty) {
+            typeVariablesClause =
+                '<${clazz.typeVariables.map((m) => mirrors.MirrorSystem.getName(m.simpleName)).join(',')}>';
+          }
+          sb.write("""
+@patch class $className$typeVariablesClause {
+$sbPatch
+}
+""");
+          if (isDom) {
+            sb.write("""
+class $classNameImpl$typeVariablesClause extends $className implements ${_JS_LIBRARY_PREFIX}.JSObjectInterfacesDom {
+  ${classNameImpl}.internal_() : super.internal_();
+  get runtimeType => $className;
+  toString() => super.toString();
+}
+""");
+          }
+        }
+      }
+    }
+  });
+  if (sb.isNotEmpty) {
+    staticCodegen
+      ..add(uri.toString())
+      ..add("${uri}_js_interop_patch.dart")
+      ..add("""
+import 'dart:js' as ${_JS_LIBRARY_PREFIX};
+
+/**
+ * Placeholder object for cases where we need to determine exactly how many
+ * args were passed to a function.
+ */
+const ${_UNDEFINED_VAR} = const Object();
+
+${sb}
+""");
+  }
+}
+
+// Remember the @JS type to compare annotation type.
+var _atJsType = -1;
+
+void setupJsTypeCache() {
+  // Cache the @JS Type.
+  if (_atJsType == -1) {
+    var uri = new Uri(scheme: "package", path: "js/js.dart");
+    var jsLibrary = mirrors.currentMirrorSystem().libraries[uri];
+    if (jsLibrary != null) {
+      // @ JS used somewhere.
+      var jsDeclaration = jsLibrary.declarations[new Symbol("JS")];
+      _atJsType = jsDeclaration.reflectedType;
+    } else {
+      // @ JS not used in any library.
+      _atJsType = null;
+    }
+  }
+}
+
+/**
+ * Generates part files defining source code for JSObjectImpl, all DOM classes
+ * classes. This codegen  is needed so that type checks for all registered
+ * JavaScript interop classes pass.
+ * If genCachedPatches is true then the patch files don't exist this is a special
+ * signal to generate and emit the patches to stdout to be captured and put into
+ * the file sdk/lib/js/dartium/cached_patches.dart
+ */
+List<String> _generateInteropPatchFiles(
+    List<String> libraryPaths, genCachedPatches) {
+  // Cache the @JS Type.
+  if (_atJsType == -1) setupJsTypeCache();
+
+  var ret =
+      _generateExternalMethods(libraryPaths, genCachedPatches ? false : true);
+  var libraryPrefixes = new Map<mirrors.LibraryMirror, String>();
+  var prefixNames = new Set<String>();
+  var sb = new StringBuffer();
+
+  var implements = <String>[];
+  var implementsArray = <String>[];
+  var implementsDom = <String>[];
+  var listMirror = mirrors.reflectType(List);
+  var functionMirror = mirrors.reflectType(Function);
+  var jsObjectMirror = mirrors.reflectType(JSObject);
+
+  for (var typeMirror in jsInterfaceTypes) {
+    mirrors.LibraryMirror libraryMirror = typeMirror.owner;
+    var location = libraryMirror.location;
+    var dartLibrary = location != null && location.sourceUri.scheme == 'dart';
+
+    var prefixName;
+    if (libraryPrefixes.containsKey(libraryMirror)) {
+      prefixName = libraryPrefixes[libraryMirror];
+    } else {
+      var basePrefixName =
+          mirrors.MirrorSystem.getName(libraryMirror.simpleName);
+      basePrefixName = basePrefixName.replaceAll('.', '_');
+      if (basePrefixName.isEmpty) basePrefixName = "lib";
+      prefixName = basePrefixName;
+      var i = 1;
+      while (prefixNames.contains(prefixName)) {
+        prefixName = '$basePrefixName$i';
+        i++;
+      }
+      prefixNames.add(prefixName);
+      libraryPrefixes[libraryMirror] = prefixName;
+    }
+    var isArray = typeMirror.isSubtypeOf(listMirror);
+    var isFunction = typeMirror.isSubtypeOf(functionMirror);
+    var isJSObject = typeMirror.isSubtypeOf(jsObjectMirror);
+    var className = mirrors.MirrorSystem.getName(typeMirror.simpleName);
+    var isPrivateUserDefinedClass = className.startsWith('_') && !dartLibrary;
+    if (isPrivateUserDefinedClass)
+      className = '${escapePrivateClassPrefix}${className}';
+    var fullName = '${prefixName}.${className}';
+    (isArray ? implementsArray : implements).add(fullName);
+    if (!isArray && !isFunction && !isJSObject) {
+      // For DOM classes we need to be a bit more conservative at tagging them
+      // as implementing JS interop classes risks strange unintended
+      // consequences as unrleated code may have instanceof checks.  Checking
+      // for isJSObject ensures we do not accidentally pull in existing
+      // dart:html classes as they all have JSObject as a base class.
+      // Note that methods from these classes can still be called on a
+      // dart:html instance but checked mode type checks will fail. This is
+      // not ideal but is better than causing strange breaks in existing
+      // code that uses dart:html.
+      // TODO(jacobr): consider throwing compile time errors if @JS classes
+      // extend JSObject as that case cannot be safely handled in Dartium.
+      implementsDom.add(fullName);
+    }
+  }
+  libraryPrefixes.forEach((libraryMirror, prefix) {
+    sb.writeln('import "${libraryMirror.uri}" as $prefix;');
+  });
+  buildImplementsClause(classes) =>
+      classes.isEmpty ? "" : "implements ${classes.join(', ')}";
+  var implementsClause = buildImplementsClause(implements);
+  var implementsClauseDom = buildImplementsClause(implementsDom);
+  // TODO(jacobr): only certain classes need to be implemented by
+  // JsFunctionImpl.
+  var allTypes = []..addAll(implements)..addAll(implementsArray);
+  sb.write('''
+class JSObjectImpl extends JSObject $implementsClause {
+  JSObjectImpl.internal() : super.internal();
+}
+
+class JSFunctionImpl extends JSFunction $implementsClause {
+  JSFunctionImpl.internal() : super.internal();
+}
+
+class JSArrayImpl extends JSArray ${buildImplementsClause(implementsArray)} {
+  JSArrayImpl.internal() : super.internal();
+}
+
+// Interfaces that are safe to slam on all DOM classes.
+// Adding implementsClause would be risky as it could contain Function which
+// is likely to break a lot of instanceof checks.
+abstract class JSObjectInterfacesDom $implementsClauseDom {
+}
+
+@patch class JSObject {
+  static Type get instanceRuntimeType => JSObjectImpl;
+}
+
+@patch class JSFunction {
+  static Type get instanceRuntimeType => JSFunctionImpl;
+}
+
+@patch class JSArray {
+  static Type get instanceRuntimeType => JSArrayImpl;
+}
+
+_registerAllJsInterfaces() {
+  _registerJsInterfaces([${allTypes.join(", ")}]);
+}
+
+''');
+  ret..addAll(["dart:js", "JSInteropImpl.dart", sb.toString()]);
+  return ret;
+}
+
+// Start of block of helper methods facilitating emulating JavaScript Array
+// methods on Dart List objects passed to JavaScript via JS interop.
+// TODO(jacobr): match JS more closely.
+String _toStringJs(obj) => '$obj';
+
+// TODO(jacobr): this might not exactly match JS semantics but should be
+// adequate for now.
+int _toIntJs(obj) {
+  if (obj is int) return obj;
+  if (obj is num) return obj.toInt();
+  return num.parse('$obj'.trim(), (_) => 0).toInt();
+}
+
+// TODO(jacobr): this might not exactly match JS semantics but should be
+// adequate for now.
+num _toNumJs(obj) {
+  return obj is num ? obj : num.parse('$obj'.trim(), (_) => 0);
+}
+
+/// Match the behavior of setting List length in JavaScript with the exception
+/// that Dart does not distinguish undefined and null.
+_setListLength(List list, rawlen) {
+  num len = _toNumJs(rawlen);
+  if (len is! int || len < 0) {
+    throw new RangeError("Invalid array length");
+  }
+  if (len > list.length) {
+    _arrayExtend(list, len);
+  } else if (len < list.length) {
+    list.removeRange(len, list.length);
+  }
+  return rawlen;
+}
+
+// TODO(jacobr): should we really bother with this method instead of just
+// shallow copying to a JS array and calling the JavaScript join method?
+String _arrayJoin(List list, sep) {
+  if (sep == null) {
+    sep = ",";
+  }
+  return list.map((e) => e == null ? "" : e.toString()).join(sep.toString());
+}
+
+// TODO(jacobr): should we really bother with this method instead of just
+// shallow copying to a JS array and using the toString method?
+String _arrayToString(List list) => _arrayJoin(list, ",");
+
+int _arrayPush(List list, List args) {
+  for (var e in args) {
+    list.add(e);
+  }
+  return list.length;
+}
+
+_arrayPop(List list) {
+  if (list.length > 0) return list.removeLast();
+}
+
+// TODO(jacobr): would it be better to just copy input to a JS List
+// and call Array.concat?
+List _arrayConcat(List input, List args) {
+  var ret = new List.from(input);
+  for (var e in args) {
+    // TODO(jacobr): technically in ES6 we should use
+    // Symbol.isConcatSpreadable to determine whether call addAll. Once v8
+    // supports it, we can make all Dart classes implementing Iterable
+    // specify isConcatSpreadable and tweak this behavior to allow Iterable.
+    if (e is List) {
+      ret.addAll(e);
+    } else {
+      ret.add(e);
+    }
+  }
+  return ret;
+}
+
+List _arraySplice(List input, List args) {
+  int start = 0;
+  if (args.length > 0) {
+    var rawStart = _toIntJs(args[0]);
+    if (rawStart < 0) {
+      start = math.max(0, input.length - rawStart);
+    } else {
+      start = math.min(input.length, rawStart);
+    }
+  }
+  var end = start;
+  if (args.length > 1) {
+    var rawDeleteCount = _toIntJs(args[1]);
+    if (rawDeleteCount < 0) rawDeleteCount = 0;
+    end = math.min(input.length, start + rawDeleteCount);
+  }
+  var replacement = [];
+  var removedElements = input.getRange(start, end).toList();
+  if (args.length > 2) {
+    replacement = args.getRange(2, args.length);
+  }
+  input.replaceRange(start, end, replacement);
+  return removedElements;
+}
+
+List _arrayReverse(List l) {
+  for (var i = 0, j = l.length - 1; i < j; i++, j--) {
+    var tmp = l[i];
+    l[i] = l[j];
+    l[j] = tmp;
+  }
+  return l;
+}
+
+_arrayShift(List l) {
+  if (l.isEmpty) return null; // Technically we should return undefined.
+  return l.removeAt(0);
+}
+
+int _arrayUnshift(List l, List args) {
+  l.insertAll(0, args);
+  return l.length;
+}
+
+_arrayExtend(List l, int newLength) {
+  for (var i = l.length; i < newLength; i++) {
+    // TODO(jacobr): we'd really like to add undefined to better match
+    // JavaScript semantics.
+    l.add(null);
+  }
+}
+
+List _arraySort(List l, rawCompare) {
+  // TODO(jacobr): alternately we could just copy the Array to JavaScript,
+  // invoke the JS sort method and then copy the result back to Dart.
+  Comparator compare;
+  if (rawCompare == null) {
+    compare = (a, b) => _toStringJs(a).compareTo(_toStringJs(b));
+  } else if (rawCompare is JsFunction) {
+    compare = (a, b) => rawCompare.apply([a, b]);
+  } else {
+    compare = rawCompare;
+  }
+  l.sort(compare);
+  return l;
+}
+// End of block of helper methods to emulate JavaScript Array methods on Dart List.
+
+/**
+ * Can be called to provide a predictable point where no more JS interfaces can
+ * be added. Creating an instance of JsObject will also automatically trigger
+ * all JsObjects to be finalized.
+ */
+@Deprecated("Internal Use Only")
+void finalizeJsInterfaces() {
+  if (_finalized == true) {
+    throw 'JSInterop class registration already finalized';
+  }
+  _finalizeJsInterfaces();
+}
+
+JsObject _cachedContext;
+
+JsObject get _context native "Js_context_Callback";
+
+bool get _finalized native "Js_interfacesFinalized_Callback";
+
+JsObject get context {
+  if (_cachedContext == null) {
+    _cachedContext = _context;
+  }
+  return _cachedContext;
+}
+
+_lookupType(o, bool isCrossFrame, bool isElement) {
+  try {
+    var type = html_common.lookupType(o, isElement);
+    var typeMirror = mirrors.reflectType(type);
+    var legacyInteropConvertToNative =
+        typeMirror.isSubtypeOf(mirrors.reflectType(html.Blob)) ||
+            typeMirror.isSubtypeOf(mirrors.reflectType(html.Event)) ||
+            typeMirror.isSubtypeOf(mirrors.reflectType(indexed_db.KeyRange)) ||
+            typeMirror.isSubtypeOf(mirrors.reflectType(html.ImageData)) ||
+            typeMirror.isSubtypeOf(mirrors.reflectType(html.Node)) ||
+//        TypedData is removed from this list as it is converted directly
+//        rather than flowing through the interceptor code path.
+//        typeMirror.isSubtypeOf(mirrors.reflectType(typed_data.TypedData)) ||
+            typeMirror.isSubtypeOf(mirrors.reflectType(html.Window));
+    if (isCrossFrame &&
+        !typeMirror.isSubtypeOf(mirrors.reflectType(html.Window))) {
+      // TODO(jacobr): evaluate using the true cross frame Window class, etc.
+      // as well as triggering that legacy JS Interop returns raw JsObject
+      // instances.
+      legacyInteropConvertToNative = false;
+    }
+    return [type, legacyInteropConvertToNative];
+  } catch (e) {}
+  return [JSObject.instanceRuntimeType, false];
+}
+
+/**
+ * Base class for both the legacy JsObject class and the modern JSObject class.
+ * This allows the JsNative utility class tobehave identically whether it is
+ * called on a JsObject or a JSObject.
+ */
+class _JSObjectBase extends NativeFieldWrapperClass2 {
+  String _toString() native "JSObject_toString";
+  _callMethod(String name, List args) native "JSObject_callMethod";
+  _operator_getter(String property) native "JSObject_[]";
+  _operator_setter(String property, value) native "JSObject_[]=";
+  bool _hasProperty(String property) native "JsObject_hasProperty";
+  bool _instanceof(/*JsFunction|JSFunction*/ type) native "JsObject_instanceof";
+
+  int get hashCode native "JSObject_hashCode";
+}
+
+/**
+ * Proxies a JavaScript object to Dart.
+ *
+ * The properties of the JavaScript object are accessible via the `[]` and
+ * `[]=` operators. Methods are callable via [callMethod].
+ */
+class JsObject extends _JSObjectBase {
+  JsObject.internal();
+
+  /**
+   * Constructs a new JavaScript object from [constructor] and returns a proxy
+   * to it.
+   */
+  factory JsObject(JsFunction constructor, [List arguments]) {
+    try {
+      return _create(constructor, arguments);
+    } catch (e) {
+      // Re-throw any errors (returned as a string) as a DomException.
+      throw new html.DomException.jsInterop(e);
+    }
+  }
+
+  static JsObject _create(JsFunction constructor, arguments)
+      native "JsObject_constructorCallback";
+
+  /**
+   * Constructs a [JsObject] that proxies a native Dart object; _for expert use
+   * only_.
+   *
+   * Use this constructor only if you wish to get access to JavaScript
+   * properties attached to a browser host object, such as a Node or Blob, that
+   * is normally automatically converted into a native Dart object.
+   *
+   * An exception will be thrown if [object] either is `null` or has the type
+   * `bool`, `num`, or `String`.
+   */
+  factory JsObject.fromBrowserObject(object) {
+    if (object is num || object is String || object is bool || object == null) {
+      throw new ArgumentError("object cannot be a num, string, bool, or null");
+    }
+    if (object is JsObject) return object;
+    return _fromBrowserObject(object);
+  }
+
+  /**
+   * Recursively converts a JSON-like collection of Dart objects to a
+   * collection of JavaScript objects and returns a [JsObject] proxy to it.
+   *
+   * [object] must be a [Map] or [Iterable], the contents of which are also
+   * converted. Maps and Iterables are copied to a new JavaScript object.
+   * Primitives and other transferrable values are directly converted to their
+   * JavaScript type, and all other objects are proxied.
+   */
+  factory JsObject.jsify(object) {
+    if ((object is! Map) && (object is! Iterable)) {
+      throw new ArgumentError("object must be a Map or Iterable");
+    }
+    return _jsify(object);
+  }
+
+  static JsObject _jsify(object) native "JsObject_jsify";
+
+  static JsObject _fromBrowserObject(object)
+      native "JsObject_fromBrowserObject";
+
+  /**
+   * Returns the value associated with [property] from the proxied JavaScript
+   * object.
+   *
+   * The type of [property] must be either [String] or [num].
+   */
+  operator [](property) {
+    try {
+      return _operator_getterLegacy(property);
+    } catch (e) {
+      // Re-throw any errors (returned as a string) as a DomException.
+      throw new html.DomException.jsInterop(e);
+    }
+  }
+
+  _operator_getterLegacy(property) native "JsObject_[]Legacy";
+
+  /**
+   * Sets the value associated with [property] on the proxied JavaScript
+   * object.
+   *
+   * The type of [property] must be either [String] or [num].
+   */
+  operator []=(property, value) {
+    try {
+      _operator_setterLegacy(property, value);
+    } catch (e) {
+      // Re-throw any errors (returned as a string) as a DomException.
+      throw new html.DomException.jsInterop(e);
+    }
+  }
+
+  _operator_setterLegacy(property, value) native "JsObject_[]=Legacy";
+
+  int get hashCode native "JsObject_hashCode";
+
+  operator ==(other) {
+    if (other is! JsObject && other is! JSObject) return false;
+    return _identityEquality(this, other);
+  }
+
+  static bool _identityEquality(a, b) native "JsObject_identityEquality";
+
+  /**
+   * Returns `true` if the JavaScript object contains the specified property
+   * either directly or though its prototype chain.
+   *
+   * This is the equivalent of the `in` operator in JavaScript.
+   */
+  bool hasProperty(String property) => _hasProperty(property);
+
+  /**
+   * Removes [property] from the JavaScript object.
+   *
+   * This is the equivalent of the `delete` operator in JavaScript.
+   */
+  void deleteProperty(String property) native "JsObject_deleteProperty";
+
+  /**
+   * Returns `true` if the JavaScript object has [type] in its prototype chain.
+   *
+   * This is the equivalent of the `instanceof` operator in JavaScript.
+   */
+  bool instanceof(JsFunction type) => _instanceof(type);
+
+  /**
+   * Returns the result of the JavaScript objects `toString` method.
+   */
+  String toString() {
+    try {
+      return _toString();
+    } catch (e) {
+      return super.toString();
+    }
+  }
+
+  String _toString() native "JsObject_toString";
+
+  /**
+   * Calls [method] on the JavaScript object with the arguments [args] and
+   * returns the result.
+   *
+   * The type of [method] must be either [String] or [num].
+   */
+  callMethod(String method, [List args]) {
+    try {
+      return _callMethodLegacy(method, args);
+    } catch (e) {
+      if (hasProperty(method)) {
+        // Return a DomException if DOM call returned an error.
+        throw new html.DomException.jsInterop(e);
+      } else {
+        throw new NoSuchMethodError(this, new Symbol(method), args, null);
+      }
+    }
+  }
+
+  _callMethodLegacy(String name, List args) native "JsObject_callMethodLegacy";
+}
+
+/// Base class for all JS objects used through dart:html and typed JS interop.
+@Deprecated("Internal Use Only")
+class JSObject extends _JSObjectBase {
+  JSObject.internal() {}
+  external static Type get instanceRuntimeType;
+
+  /**
+   * Returns the result of the JavaScript objects `toString` method.
+   */
+  String toString() {
+    try {
+      return _toString();
+    } catch (e) {
+      return super.toString();
+    }
+  }
+
+  noSuchMethod(Invocation invocation) {
+    throwError() {
+      super.noSuchMethod(invocation);
+    }
+
+    String name = _stripReservedNamePrefix(
+        mirrors.MirrorSystem.getName(invocation.memberName));
+    argsSafeForTypedInterop(invocation.positionalArguments);
+    if (invocation.isGetter) {
+      if (CHECK_JS_INVOCATIONS) {
+        var matches = _allowedGetters[invocation.memberName];
+        if (matches == null &&
+            !_allowedMethods.containsKey(invocation.memberName)) {
+          throwError();
+        }
+        var ret = _operator_getter(name);
+        if (matches != null) return ret;
+        if (ret is Function ||
+            (ret is JsFunction /* shouldn't be needed in the future*/) &&
+                _allowedMethods.containsKey(invocation.memberName))
+          return ret; // Warning: we have not bound "this"... we could type check on the Function but that is of little value in Dart.
+        throwError();
+      } else {
+        // TODO(jacobr): should we throw if the JavaScript object doesn't have the property?
+        return _operator_getter(name);
+      }
+    } else if (invocation.isSetter) {
+      if (CHECK_JS_INVOCATIONS) {
+        var matches = _allowedSetters[invocation.memberName];
+        if (matches == null || !matches.checkInvocation(invocation))
+          throwError();
+      }
+      assert(name.endsWith("="));
+      name = name.substring(0, name.length - 1);
+      return _operator_setter(name, invocation.positionalArguments.first);
+    } else {
+      // TODO(jacobr): also allow calling getters that look like functions.
+      var matches;
+      if (CHECK_JS_INVOCATIONS) {
+        matches = _allowedMethods[invocation.memberName];
+        if (matches == null || !matches.checkInvocation(invocation))
+          throwError();
+      }
+      var ret = _callMethod(name, _buildArgs(invocation));
+      if (CHECK_JS_INVOCATIONS) {
+        if (!matches._checkReturnType(ret)) {
+          html.window.console.error("Return value for method: ${name} is "
+              "${ret.runtimeType} which is inconsistent with all typed "
+              "JS interop definitions for method ${name}.");
+        }
+      }
+      return ret;
+    }
+  }
+}
+
+@Deprecated("Internal Use Only")
+class JSArray extends JSObject with ListMixin {
+  JSArray.internal() : super.internal();
+  external static Type get instanceRuntimeType;
+
+  // Reuse JsArray_length as length behavior is unchanged.
+  int get length native "JsArray_length";
+
+  set length(int length) {
+    _operator_setter('length', length);
+  }
+
+  _checkIndex(int index, {bool insert: false}) {
+    int length = insert ? this.length + 1 : this.length;
+    if (index is int && (index < 0 || index >= length)) {
+      throw new RangeError.range(index, 0, length);
+    }
+  }
+
+  _checkRange(int start, int end) {
+    int cachedLength = this.length;
+    if (start < 0 || start > cachedLength) {
+      throw new RangeError.range(start, 0, cachedLength);
+    }
+    if (end < start || end > cachedLength) {
+      throw new RangeError.range(end, start, cachedLength);
+    }
+  }
+
+  _indexed_getter(int index) native "JSArray_indexed_getter";
+  _indexed_setter(int index, o) native "JSArray_indexed_setter";
+
+  // Methods required by ListMixin
+
+  operator [](index) {
+    if (index is int) {
+      _checkIndex(index);
+    }
+
+    return _indexed_getter(index);
+  }
+
+  void operator []=(int index, value) {
+    _checkIndex(index);
+    _indexed_setter(index, value);
+  }
+}
+
+@Deprecated("Internal Use Only")
+class JSFunction extends JSObject implements Function {
+  JSFunction.internal() : super.internal();
+
+  external static Type get instanceRuntimeType;
+
+  call(
+      [a1 = _UNDEFINED,
+      a2 = _UNDEFINED,
+      a3 = _UNDEFINED,
+      a4 = _UNDEFINED,
+      a5 = _UNDEFINED,
+      a6 = _UNDEFINED,
+      a7 = _UNDEFINED,
+      a8 = _UNDEFINED,
+      a9 = _UNDEFINED,
+      a10 = _UNDEFINED]) {
+    return _apply(
+        _stripUndefinedArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10]));
+  }
+
+  noSuchMethod(Invocation invocation) {
+    if (invocation.isMethod && invocation.memberName == #call) {
+      return _apply(_buildArgs(invocation));
+    }
+    return super.noSuchMethod(invocation);
+  }
+
+  dynamic _apply(List args, {thisArg}) native "JSFunction_apply";
+
+  static JSFunction _createWithThis(Function f)
+      native "JSFunction_createWithThis";
+  static JSFunction _create(Function f) native "JSFunction_create";
+}
+
+// JavaScript interop methods that do not automatically wrap to dart:html types.
+// Warning: this API is not exposed to dart:js.
+// TODO(jacobr): rename to JSNative and make at least part of this API public.
+@Deprecated("Internal Use Only")
+class JsNative {
+  static JSObject jsify(object) native "JSObject_jsify";
+  static JSObject newObject() native "JSObject_newObject";
+  static JSArray newArray() native "JSObject_newArray";
+
+  static hasProperty(_JSObjectBase o, name) => o._hasProperty(name);
+  static getProperty(_JSObjectBase o, name) => o._operator_getter(name);
+  static setProperty(_JSObjectBase o, name, value) =>
+      o._operator_setter(name, value);
+  static callMethod(_JSObjectBase o, String method, List args) =>
+      o._callMethod(method, args);
+  static instanceof(_JSObjectBase o, /*JsFunction|JSFunction*/ type) =>
+      o._instanceof(type);
+  static callConstructor0(_JSObjectBase constructor)
+      native "JSNative_callConstructor0";
+  static callConstructor(_JSObjectBase constructor, List args)
+      native "JSNative_callConstructor";
+
+  static toTypedObject(JsObject o) native "JSNative_toTypedObject";
+
+  /**
+   * Same behavior as new JsFunction.withThis except that JavaScript "this" is not
+   * wrapped.
+   */
+  static JSFunction withThis(Function f) native "JsFunction_withThisNoWrap";
+}
+
+/**
+ * Proxies a JavaScript Function object.
+ */
+class JsFunction extends JsObject {
+  JsFunction.internal() : super.internal();
+
+  /**
+   * Returns a [JsFunction] that captures its 'this' binding and calls [f]
+   * with the value of this passed as the first argument.
+   */
+  factory JsFunction.withThis(Function f) => _withThis(f);
+
+  /**
+   * Invokes the JavaScript function with arguments [args]. If [thisArg] is
+   * supplied it is the value of `this` for the invocation.
+   */
+  dynamic apply(List args, {thisArg}) => _apply(args, thisArg: thisArg);
+
+  dynamic _apply(List args, {thisArg}) native "JsFunction_apply";
+
+  /**
+   * Internal only version of apply which uses debugger proxies of Dart objects
+   * rather than opaque handles. This method is private because it cannot be
+   * efficiently implemented in Dart2Js so should only be used by internal
+   * tools.
+   */
+  _applyDebuggerOnly(List args, {thisArg})
+      native "JsFunction_applyDebuggerOnly";
+
+  static JsFunction _withThis(Function f) native "JsFunction_withThis";
+}
+
+/**
+ * A [List] proxying a JavaScript Array.
+ */
+class JsArray<E> extends JsObject with ListMixin<E> {
+  JsArray.internal() : super.internal();
+
+  factory JsArray() => _newJsArray();
+
+  static JsArray _newJsArray() native "JsArray_newJsArray";
+
+  factory JsArray.from(Iterable<E> other) =>
+      _newJsArrayFromSafeList(new List.from(other));
+
+  static JsArray _newJsArrayFromSafeList(List list)
+      native "JsArray_newJsArrayFromSafeList";
+
+  _checkIndex(int index, {bool insert: false}) {
+    int length = insert ? this.length + 1 : this.length;
+    if (index is int && (index < 0 || index >= length)) {
+      throw new RangeError.range(index, 0, length);
+    }
+  }
+
+  _checkRange(int start, int end) {
+    int cachedLength = this.length;
+    if (start < 0 || start > cachedLength) {
+      throw new RangeError.range(start, 0, cachedLength);
+    }
+    if (end < start || end > cachedLength) {
+      throw new RangeError.range(end, start, cachedLength);
+    }
+  }
+
+  // Methods required by ListMixin
+
+  E operator [](index) {
+    if (index is int) {
+      _checkIndex(index);
+    }
+
+    return super[index];
+  }
+
+  void operator []=(index, E value) {
+    if (index is int) {
+      _checkIndex(index);
+    }
+    super[index] = value;
+  }
+
+  int get length native "JsArray_length";
+
+  set length(int length) {
+    super['length'] = length;
+  }
+
+  // Methods overridden for better performance
+
+  void add(E value) {
+    callMethod('push', [value]);
+  }
+
+  void addAll(Iterable<E> iterable) {
+    // TODO(jacobr): this can be optimized slightly.
+    callMethod('push', new List.from(iterable));
+  }
+
+  void insert(int index, E element) {
+    _checkIndex(index, insert: true);
+    callMethod('splice', [index, 0, element]);
+  }
+
+  E removeAt(int index) {
+    _checkIndex(index);
+    return callMethod('splice', [index, 1])[0];
+  }
+
+  E removeLast() {
+    if (length == 0) throw new RangeError(-1);
+    return callMethod('pop');
+  }
+
+  void removeRange(int start, int end) {
+    _checkRange(start, end);
+    callMethod('splice', [start, end - start]);
+  }
+
+  void setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) {
+    _checkRange(start, end);
+    int length = end - start;
+    if (length == 0) return;
+    if (skipCount < 0) throw new ArgumentError(skipCount);
+    var args = [start, length]..addAll(iterable.skip(skipCount).take(length));
+    callMethod('splice', args);
+  }
+
+  void sort([int compare(E a, E b)]) {
+    callMethod('sort', [compare]);
+  }
+}
+
+/**
+ * Placeholder object for cases where we need to determine exactly how many
+ * args were passed to a function.
+ */
+const _UNDEFINED = const Object();
+
+// TODO(jacobr): this method is a hack to work around the lack of proper dart
+// support for varargs methods.
+List _stripUndefinedArgs(List args) =>
+    args.takeWhile((i) => i != _UNDEFINED).toList();
+
+/**
+ * Check that that if [arg] is a [Function] it is safe to pass to JavaScript.
+ * To make a function safe, call [allowInterop] or [allowInteropCaptureThis].
+ */
+@Deprecated("Internal Use Only")
+safeForTypedInterop(arg) {
+  if (CHECK_JS_INVOCATIONS && arg is Function && arg is! JSFunction) {
+    throw new ArgumentError(
+        "Attempt to pass Function '$arg' to JavaScript via without calling allowInterop or allowInteropCaptureThis");
+  }
+}
+
+/**
+ * Check that that if any elements of [args] are [Function] it is safe to pass
+ * to JavaScript. To make a function safe, call [allowInterop] or
+ * [allowInteropCaptureThis].
+ */
+@Deprecated("Internal Use Only")
+void argsSafeForTypedInterop(Iterable args) {
+  for (var arg in args) {
+    safeForTypedInterop(arg);
+  }
+}
+
+/**
+ * Returns a method that can be called with an arbitrary number (for n less
+ * than 11) of arguments without violating Dart type checks.
+ */
+Function _wrapAsDebuggerVarArgsFunction(JsFunction jsFunction) => (
+        [a1 = _UNDEFINED,
+        a2 = _UNDEFINED,
+        a3 = _UNDEFINED,
+        a4 = _UNDEFINED,
+        a5 = _UNDEFINED,
+        a6 = _UNDEFINED,
+        a7 = _UNDEFINED,
+        a8 = _UNDEFINED,
+        a9 = _UNDEFINED,
+        a10 = _UNDEFINED]) =>
+    jsFunction._applyDebuggerOnly(
+        _stripUndefinedArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10]));
+
+/// Returns a wrapper around function [f] that can be called from JavaScript
+/// using the package:js Dart-JavaScript interop.
+///
+/// For performance reasons in Dart2Js, by default Dart functions cannot be
+/// passed directly to JavaScript unless this method is called to create
+/// a Function compatible with both Dart and JavaScript.
+/// Calling this method repeatedly on a function will return the same function.
+/// The [Function] returned by this method can be used from both Dart and
+/// JavaScript. We may remove the need to call this method completely in the
+/// future if Dart2Js is refactored so that its function calling conventions
+/// are more compatible with JavaScript.
+Function/*=F*/ allowInterop/*<F extends Function>*/(Function/*=F*/ f) {
+  if (f is JSFunction) {
+    // The function is already a JSFunction... no need to do anything.
+    return f;
+  } else {
+    return JSFunction._create(f);
+  }
+}
+
+/// Cached JSFunction associated with the Dart function when "this" is
+/// captured.
+Expando<JSFunction> _interopCaptureThisExpando = new Expando<JSFunction>();
+
+/// Returns a [Function] that when called from JavaScript captures its 'this'
+/// binding and calls [f] with the value of this passed as the first argument.
+/// When called from Dart, [null] will be passed as the first argument.
+///
+/// See the documentation for [allowInterop]. This method should only be used
+/// with package:js Dart-JavaScript interop.
+JSFunction allowInteropCaptureThis(Function f) {
+  if (f is JSFunction) {
+    // Behavior when the function is already a JS function is unspecified.
+    throw new ArgumentError(
+        "Function is already a JS function so cannot capture this.");
+    return f;
+  } else {
+    var ret = _interopCaptureThisExpando[f];
+    if (ret == null) {
+      // TODO(jacobr): we could optimize this.
+      ret = JSFunction._createWithThis(f);
+      _interopCaptureThisExpando[f] = ret;
+    }
+    return ret;
+  }
+}