replace deprecated __proto__ from js code (#2500)

* replace deprecated __proto__ from js code

* updated changelog

* Update dwds/lib/src/debugging/inspector.dart

Co-authored-by: Derek Xu <[email protected]>

* Update dwds/CHANGELOG.md

Co-authored-by: Derek Xu <[email protected]>

---------

Co-authored-by: Derek Xu <[email protected]>

Author: jyameo

dwds/CHANGELOG.md

@@ -1,4 +1,5 @@
 ## 24.2.0-wip
+- Replace deprecated JS code `this.__proto__` with `Object.getPrototypeOf(this)` - [#2500](https://github.com/dart-lang/webdev/pull/2500)
 
 ## 24.1.0
 

dwds/lib/src/debugging/inspector.dart

@@ -215,7 +215,7 @@ class AppInspector implements AppInspectorInterface {
     // We use the JS pseudo-variable 'arguments' to get the list of all arguments.
     final send = '''
         function () {
-          if (!(this.__proto__)) { return 'Instance of PlainJavaScriptObject';}
+          if (!Object.getPrototypeOf(this)) { return 'Instance of PlainJavaScriptObject';}
           return ${globalToolConfiguration.loadStrategy.loadModuleSnippet}("dart_sdk").dart.dsendRepl(this, "$methodName", arguments);
         }
         ''';