Add tests for webRequest events and frame unload

chrome/test/data/extensions/api_test/webrequest/test_unload1.js

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+runTests([
+  // Opens a cross-origin iframe (a http-URL in this chrome-extension tab) and
+  // removes it.
+  function insertSlowCrossOriginFrameAndRemove() {
+    const url = getSlowURL('frame-in-extension-url');
+
+    expect([
+      { label: 'onBeforeRequest',
+        event: 'onBeforeRequest',
+        details: {
+          type: 'sub_frame',
+          url,
+          frameId: 1,
+          parentFrameId: 0,
+          frameUrl: url,
+          tabId: 1,
+        }
+      },
+      { label: 'onBeforeSendHeaders',
+        event: 'onBeforeSendHeaders',
+        details: {
+          type: 'sub_frame',
+          url,
+          frameId: 1,
+          parentFrameId: 0,
+          tabId: 1,
+        },
+      },
+      { label: 'onSendHeaders',
+        event: 'onSendHeaders',
+        details: {
+          type: 'sub_frame',
+          url,
+          frameId: 1,
+          parentFrameId: 0,
+          tabId: 1,
+        },
+      },
+      { label: 'onErrorOccurred',
+        event: 'onErrorOccurred',
+        details: {
+          type: 'sub_frame',
+          url,
+          frameId: 1,
+          parentFrameId: 0,
+          tabId: 1,
+          fromCache: false,
+          error: 'net::ERR_ABORTED',
+        },
+      }],
+      [['onBeforeRequest', 'onBeforeSendHeaders', 'onSendHeaders',
+        'onErrorOccurred']]);
+
+    var f = document.createElement('iframe');
+    f.src = url;
+    waitUntilSendHeaders('sub_frame', url, function() {
+      f.remove();
+    });
+    document.body.appendChild(f);
+  },
+]);