feat(OOPIF): debug message in case of iFrame moved to another process (#6432)

Debug message clarifying the problem like `Issue 1060080: Event Network.loadingFinished is not sent when a frame is loaded from another domain`: https://bugs.chromium.org/p/chromium/issues/detail?id=1060080).
It can help users to identify problem with OOPIF easier without digging into the CDP protocol implementation like in the bug `1060080` mentioned above.

To reproduce:
1. Run `DEBUG="puppeteer:frame" NODE_PATH=../ node examples/oopif.js`.
2. Verify the output contains the debug message:
`
puppeteer:frame The frame '...' moved to another session. Out-of-proccess
iframes (OOPIF) are not supported by Puppeteer yet.
https://github.com/puppeteer/puppeteer/issues/2548
`

examples/oopif.js

@@ -0,0 +1,47 @@
+/**
+ * Copyright 2020 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+
+const puppeteer = require('puppeteer');
+
+async function attachFrame(frameId, url) {
+  const frame = document.createElement('iframe');
+  frame.src = url;
+  frame.id = frameId;
+  document.body.appendChild(frame);
+  await new Promise((x) => (frame.onload = x));
+  return frame;
+}
+
+(async () => {
+  // Launch browser in non-headless mode.
+  const browser = await puppeteer.launch({ headless: false });
+  const page = await browser.newPage();
+
+  // Load a page from one origin:
+  await page.goto('http://example.org/');
+
+  // Inject iframe with the another origin.
+  await page.evaluateHandle(attachFrame, 'frame1', 'https://example.com/');
+
+  // At this point there should be a message in the output:
+  // puppeteer:frame The frame '...' moved to another session. Out-of-proccess
+  // iframes (OOPIF) are not supported by Puppeteer yet.
+  // https://github.com/puppeteer/puppeteer/issues/2548
+
+  await browser.close();
+})();

src/common/FrameManager.ts

@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import { debug } from '../common/Debug.js';
+
 import { EventEmitter } from './EventEmitter.js';
 import { assert } from './assert.js';
 import { helper, debugError } from './helper.js';
@@ -111,6 +113,9 @@ export class FrameManager extends EventEmitter {
     this._client.on('Page.lifecycleEvent', (event) =>
       this._onLifecycleEvent(event)
     );
+    this._client.on('Target.attachedToTarget', async (event) =>
+      this._onFrameMoved(event)
+    );
   }
 
   async initialize(): Promise<void> {
@@ -213,6 +218,20 @@ export class FrameManager extends EventEmitter {
     return watcher.navigationResponse();
   }
 
+  private async _onFrameMoved(event: Protocol.Target.AttachedToTargetEvent) {
+    if (event.targetInfo.type !== 'iframe') {
+      return;
+    }
+
+    // TODO(sadym): Remove debug message once proper OOPIF support is
+    // implemented: https://github.com/puppeteer/puppeteer/issues/2548
+    debug('puppeteer:frame')(
+      `The frame '${event.targetInfo.targetId}' moved to another session. ` +
+        `Out-of-process iframes (OOPIF) are not supported by Puppeteer yet. ` +
+        `https://github.com/puppeteer/puppeteer/issues/2548`
+    );
+  }
+
   _onLifecycleEvent(event: Protocol.Page.LifecycleEventEvent): void {
     const frame = this._frames.get(event.frameId);
     if (!frame) return;