chore: expose Connection methods relevant for extension (#8594)

src/common/Connection.ts

@@ -66,7 +66,7 @@ export class Connection extends EventEmitter {
     this.#delay = delay;
 
     this.#transport = transport;
-    this.#transport.onmessage = this.#onMessage.bind(this);
+    this.#transport.onmessage = this.onMessage.bind(this);
     this.#transport.onclose = this.#onClose.bind(this);
   }
 
@@ -81,6 +81,13 @@ export class Connection extends EventEmitter {
     return this.#closed;
   }
 
+  /**
+   * @internal
+   */
+  get _sessions(): Map<string, CDPSession> {
+    return this.#sessions;
+  }
+
   /**
    * @param sessionId - The session id
    * @returns The current CDP session if it exists
@@ -126,7 +133,10 @@ export class Connection extends EventEmitter {
     return id;
   }
 
-  async #onMessage(message: string): Promise<void> {
+  /**
+   * @internal
+   */
+  protected async onMessage(message: string): Promise<void> {
     if (this.#delay) {
       await new Promise(f => {
         return setTimeout(f, this.#delay);