refactor: cleanup global variable declarations (#38410)

refactor: eliminate duplicate isolatedApi typing

Co-authored-by: Milan Burda <miburda@microsoft.com>

lib/isolated_renderer/init.ts

@@ -1,6 +1,7 @@
-/* global isolatedApi */
-
 import type * as webViewElementModule from '@electron/internal/renderer/web-view/web-view-element';
+import type { WebViewImplHooks } from '@electron/internal/renderer/web-view/web-view-impl';
+
+declare const isolatedApi: WebViewImplHooks;
 
 if (isolatedApi.guestViewInternal) {
   // Must setup the WebView element in main world.

lib/sandboxed_renderer/init.ts

@@ -1,10 +1,15 @@
-/* global binding */
 import * as events from 'events';
 import { IPC_MESSAGES } from '@electron/internal/common/ipc-messages';
 
 import type * as ipcRendererUtilsModule from '@electron/internal/renderer/ipc-renderer-internal-utils';
 import type * as ipcRendererInternalModule from '@electron/internal/renderer/ipc-renderer-internal';
 
+declare const binding: {
+  get: (name: string) => any;
+  process: NodeJS.Process;
+  createPreloadScript: (src: string) => Function
+};
+
 const { EventEmitter } = events;
 
 process._linkedBinding = binding.get;

typings/internal-ambient.d.ts

@@ -1,13 +1,3 @@
-/* eslint-disable no-var */
-declare var internalBinding: any;
-declare var binding: { get: (name: string) => any; process: NodeJS.Process; createPreloadScript: (src: string) => Function };
-
-declare var isolatedApi: {
-  guestViewInternal: any;
-  allowGuestViewElementDefinition: NodeJS.InternalWebFrame['allowGuestViewElementDefinition'];
-  setIsWebView: (iframe: HTMLIFrameElement) => void;
-}
-
 declare const BUILDFLAG: (flag: boolean) => boolean;
 
 declare const ENABLE_DESKTOP_CAPTURER: boolean;