Revert "refactor: only create webContents after 'will-attach-webview' (#30311)" (#31785)

This reverts commit 6e43b0bcbf.

typings/internal-electron.d.ts

@@ -81,6 +81,7 @@ declare namespace Electron {
     attachToIframe(embedderWebContents: Electron.WebContents, embedderFrameId: number): void;
     detachFromOuterFrame(): void;
     setEmbedder(embedder: Electron.WebContents): void;
+    attachParams?: Record<string, any>;
     viewInstanceId: number;
   }