diff --git a/shell/renderer/electron_renderer_client.cc b/shell/renderer/electron_renderer_client.cc
index a7a98839fb54e..c507bdcffccbb 100644
--- a/shell/renderer/electron_renderer_client.cc
+++ b/shell/renderer/electron_renderer_client.cc
@@ -157,6 +157,7 @@ void ElectronRendererClient::WillReleaseScriptContext(
   // We also do this if we have disable electron site instance overrides to
   // avoid memory leaks
   auto prefs = render_frame->GetBlinkPreferences();
+  gin_helper::MicrotasksScope microtasks_scope(env->isolate());
   node::FreeEnvironment(env);
   if (env == node_bindings_->uv_env())
     node::FreeIsolateData(node_bindings_->isolate_data());
diff --git a/shell/renderer/web_worker_observer.cc b/shell/renderer/web_worker_observer.cc
index 2faec5ffc4347..287be9ead13f0 100644
--- a/shell/renderer/web_worker_observer.cc
+++ b/shell/renderer/web_worker_observer.cc
@@ -37,6 +37,8 @@ WebWorkerObserver::WebWorkerObserver()
 
 WebWorkerObserver::~WebWorkerObserver() {
   lazy_tls.Pointer()->Set(nullptr);
+  gin_helper::MicrotasksScope microtasks_scope(
+      node_bindings_->uv_env()->isolate());
   node::FreeEnvironment(node_bindings_->uv_env());
   node::FreeIsolateData(node_bindings_->isolate_data());
 }
diff --git a/spec/chromium-spec.js b/spec/chromium-spec.js
index 26e43b12ae749..86737f78860a1 100644
--- a/spec/chromium-spec.js
+++ b/spec/chromium-spec.js
@@ -154,16 +154,6 @@ describe('chromium feature', () => {
     });
   });
 
-  describe('window.postMessage', () => {
-    it('throws an exception when the targetOrigin cannot be converted to a string', () => {
-      const b = window.open('');
-      expect(() => {
-        b.postMessage('test', { toString: null });
-      }).to.throw('Cannot convert object to primitive value');
-      b.close();
-    });
-  });
-
   describe('window.opener.postMessage', () => {
     it('sets source and origin correctly', async () => {
       const message = waitForEvent(window, 'message');
diff --git a/spec/static/main.js b/spec/static/main.js
index f60970d3998b7..f259a3612fd31 100644
--- a/spec/static/main.js
+++ b/spec/static/main.js
@@ -109,8 +109,7 @@ app.whenReady().then(async function () {
       backgroundThrottling: false,
       nodeIntegration: true,
       webviewTag: true,
-      contextIsolation: false,
-      nativeWindowOpen: false
+      contextIsolation: false
     }
   });
   window.loadFile('static/index.html', {