Check for null prototype in isJavaScriptSimpleObject

sdk/lib/html/html_common/conversions.dart

Index: sdk/lib/html/html_common/conversions.dart
diff --git a/sdk/lib/html/html_common/conversions.dart b/sdk/lib/html/html_common/conversions.dart
index 255b3e5e65140d4161f0a1d88d24d0f22148e214..e34345285492b95fcc1d91e61d78fb447dfea310 100644
--- a/sdk/lib/html/html_common/conversions.dart
+++ b/sdk/lib/html/html_common/conversions.dart
@@ -393,7 +393,8 @@ 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);
+    JS('bool', 'Object.getPrototypeOf(#) === Object.prototype', value) ||
+    JS('bool', 'Object.getPrototypeOf(#) === null', value);

[sra1, 2015/01/29 02:32:57]

Please CSE, the compiler can't do it:

{
  var proto = JS('', 'Object.getPrototypeOf(#)', value);
  return JS('bool', '# === Object.prototype', proto) ||
         JS('bool', '# === null', proto);
}

[Alan Knight, 2015/01/29 22:52:44]

Done.

 bool isImmutableJavaScriptArray(value) =>
     JS('bool', r'!!(#.immutable$list)', value);