Get rid of ===/!===.

lib/html/src/dart2js_Conversions.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.
 
 
 // Conversions for IDBKey.
 //
 // Per http://www.w3.org/TR/IndexedDB/#key-construct
 //
 // "A value is said to be a valid key if it is one of the following types: Array
@@ skipping 181 matching lines @@
  */
 _convertDartToNative_PrepareForStructuredClone(value) {
 
   // TODO(sra): Replace slots with identity hash table.
   var values = [];
   var copies = [];  // initially 'null', 'true' during initial DFS, then a copy.
 
   int findSlot(value) {
     int length = values.length;
     for (int i = 0; i < length; i++) {
-      if (values[i] === value) return i;
+      if (identical(values[i], value)) return i;
     }
     values.add(value);
     copies.add(null);
     return length;
   }
   readSlot(int i) => copies[i];
   writeSlot(int i, x) { copies[i] = x; }
   cleanupSlots() {}  // Will be needed if we mark objects with a property.
 
   // Returns the input, or a clone of the input.
@@ skipping 78 matching lines @@
 
       if (_isJavaScriptArray(e) &&
           // We have to copy immutable lists, otherwise the structured clone
           // algorithm will copy the .immutable$list marker property, making the
           // list immutable when received!
           !_isImmutableJavaScriptArray(e)) {
         writeSlot(slot, true);  // Deferred copy.
         for ( ; i < length; i++) {
           var element = e[i];
           var elementCopy = walk(element);
-          if (elementCopy !== element) {
+          if (!identical(elementCopy, element)) {
             copy = readSlot(slot);   // Cyclic reference may have created it.
             if (true == copy) {
               copy = JS('List', 'new Array(#)', length);
               writeSlot(slot, copy);
             }
             for (int j = 0; j < i; j++) {
               copy[j] = e[j];
             }
             copy[i] = elementCopy;
             i++;
@@ skipping 45 matching lines @@
 _convertNativeToDart_AcceptStructuredClone(object, {mustCopy = false}) {
 
   // TODO(sra): Replace slots with identity hash table that works on non-dart
   // objects.
   var values = [];
   var copies = [];
 
   int findSlot(value) {
     int length = values.length;
     for (int i = 0; i < length; i++) {
-      if (values[i] === value) return i;
+      if (identical(values[i], value)) return i;
     }
     values.add(value);
     copies.add(null);
     return length;
   }
   readSlot(int i) => copies[i];
   writeSlot(int i, x) { copies[i] = x; }
 
   walk(e) {
     if (e == null) return e;
@@ skipping 53 matching lines @@
 }
 
 
 bool _isJavaScriptDate(value) => JS('bool', '# instanceof Date', value);
 bool _isJavaScriptRegExp(value) => JS('bool', '# instanceof RegExp', value);
 bool _isJavaScriptArray(value) => JS('bool', '# instanceof Array', value);
 bool _isJavaScriptSimpleObject(value) =>
     JS('bool', 'Object.getPrototypeOf(#) === Object.prototype', value);
 bool _isImmutableJavaScriptArray(value) =>
     JS('bool', r'!!(#.immutable$list)', value);