Remove dynamic call from _LinkedHashSet. Remove some dcalls from the dart:html util library.

pkg/dev_compiler/tool/input_sdk/lib/html/html_common/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 58 matching lines @@
     }
     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.
   bool cloneNotRequired(object);
   newJsMap();
-  newJsList(length);
+  List newJsList(length);
   void putIntoMap(map, key, value);
 
   // Returns the input, or a clone of the input.
   walk(e) {
     if (e == null) return e;
     if (e is bool) return e;
     if (e is num) return e;
     if (e is String) return e;
     if (e is DateTime) {
       return convertDartToNative_DateTime(e);
@@ skipping 30 matching lines @@
       return copy;
     }
 
     if (e is List) {
       // Since a JavaScript Array is an instance of Dart List it is tempting
       // in dart2js to avoid making a copy of the list if there is no need
       // to copy anything reachable from the array.  However, the list may have
       // non-native properties or methods from interceptors and such, e.g.
       // an immutability marker. So we  had to stop doing that.
       var slot = findSlot(e);
-      var copy = readSlot(slot);
+      List copy = JS('List', '#', readSlot(slot));

[vsm, 2017/02/01 18:37:13]

var copy = JS('List', ...)

should get handled the right way I think, here and a couple places below - i.e.,
no cast + inference.

[Jacob, 2017/02/01 20:33:48]

Done.

       if (copy != null) return copy;
       copy = copyList(e, slot);
       return copy;
     }
 
     throw new UnimplementedError('structured clone of other type');
   }
 
-  copyList(List e, int slot) {
+  List copyList(List e, int slot) {
     int i = 0;
     int length = e.length;
     var copy = newJsList(length);
     writeSlot(slot, copy);
     for ( ; i < length; i++) {
       copy[i] = walk(e[i]);
     }
     return copy;
   }
 
@@ skipping 39 matching lines @@
     return length;
   }
 
   /// Are the two objects identical, but taking into account that two JsObject
   /// wrappers may not be identical, but their underlying Js Object might be.
   bool identicalInJs(a, b);
   readSlot(int i) => copies[i];
   writeSlot(int i, x) { copies[i] = x; }
 
   /// Iterate over the JS properties.
-  forEachJsField(object, action);
+  forEachJsField(object, action(key, value));
 
   /// Create a new Dart list of the given length. May create a native List or
   /// a JsArray, depending if we're in Dartium or dart2js.
-  newDartList(length);
+  List newDartList(length);
 
   walk(e) {
     if (e == null) return e;
     if (e is bool) return e;
     if (e is num) return e;
     if (e is String) return e;
 
     if (isJavaScriptDate(e)) {
       return convertNativeToDart_DateTime(e);
     }
@@ skipping 14 matching lines @@
       var copy = readSlot(slot);
       if (copy != null) return copy;
       copy = {};
 
       writeSlot(slot, copy);
       forEachJsField(e, (key, value) => copy[key] = walk(value));
       return copy;
     }
 
     if (isJavaScriptArray(e)) {
-      var slot = findSlot(e);
-      var copy = readSlot(slot);
+      List l = JS('', '#', e);

[Jacob, 2017/02/01 02:17:39]

This is a fairly frequently called helper so eliminating the dynamic calls in
its internals is probably worth it even though this code is a little ugly.

+      var slot = findSlot(l);
+      List copy = JS('', '#', readSlot(slot));
       if (copy != null) return copy;
 
-      int length = e.length;
+      int length = l.length;
       // Since a JavaScript Array is an instance of Dart List, we can modify it
       // in-place unless we must copy.
-      copy = mustCopy ? newDartList(length) : e;
+      copy = mustCopy ? newDartList(length) : l;
       writeSlot(slot, copy);
 
       for (int i = 0; i < length; i++) {
-        copy[i] = walk(e[i]);
+        copy[i] = walk(l[i]);
       }
       return copy;
     }
 
     // Assume anything else is already a valid Dart object, either by having
     // already been processed, or e.g. a clonable native class.
     return e;
   }
 
   convertNativeToDart_AcceptStructuredClone(object, {mustCopy: false}) {
@@ skipping 95 matching lines @@
 const String _serializedScriptValue =
     'num|String|bool|'
     'JSExtendableArray|=Object|'
     'Blob|File|NativeByteBuffer|NativeTypedData'
     // TODO(sra): Add Date, RegExp.
     ;
 const annotation_Creates_SerializedScriptValue =
     const Creates(_serializedScriptValue);
 const annotation_Returns_SerializedScriptValue =
     const Returns(_serializedScriptValue);