fix: crash when navigating from a page with webview that has inherited zoom level (#24757)

* fix: cleanup webview zoom level observers on navigation

* add spec

* webview should be on same partition

* wait for webview to finish loading

shell/browser/api/electron_api_web_contents.cc

@@ -1413,6 +1413,11 @@ bool WebContents::OnMessageReceived(const IPC::Message& message) {
 // we need to make sure the api::WebContents is also deleted.
 // For #4, the WebContents will be destroyed by embedder.
 void WebContents::WebContentsDestroyed() {
+  // Give chance for guest delegate to cleanup its observers
+  // since the native class is only destroyed in the next tick.
+  if (guest_delegate_)
+    guest_delegate_->WillDestroy();
+
   // Cleanup relationships with other parts.
   RemoveFromWeakMap();
 

shell/browser/web_view_guest_delegate.cc

@@ -57,6 +57,10 @@ void WebViewGuestDelegate::AttachToIframe(
   api_web_contents_->Emit("did-attach");
 }
 
+void WebViewGuestDelegate::WillDestroy() {
+  ResetZoomController();
+}
+
 void WebViewGuestDelegate::DidDetach() {
   ResetZoomController();
 }

shell/browser/web_view_guest_delegate.h

@@ -24,6 +24,7 @@ class WebViewGuestDelegate : public content::BrowserPluginGuestDelegate,
   // Attach to the iframe.
   void AttachToIframe(content::WebContents* embedder_web_contents,
                       int embedder_frame_id);
+  void WillDestroy();
 
  protected:
   // content::BrowserPluginGuestDelegate: