Clear an extension's filtered events when a context is destroyed.

chrome/test/data/extensions/api_test/events_are_unregistered/page1.js

 // Copyright 2015 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.
 
+'use strict';
+
 // Register for events in 4 configurations, then navigate to page2.html, which
 // will notify success and succeed the test on the C++ side. The C++ code
 // asserts that the events have been unregistered.
 
+//
+// Unfiltered events.
+//
+
 // A single listener.
 chrome.browserAction.onClicked.addListener(function() {});
 // Multiple listeners for the same event.
 chrome.runtime.onStartup.addListener(function() {});
 chrome.runtime.onStartup.addListener(function() {});
 // A single listener, which previously had multiple listeners.
-chrome.runtime.onSuspend.addListener(function() {});
-chrome.runtime.onSuspend.addListener(function() {});
-chrome.runtime.onSuspend.removeListener(function() {});
+{
+  let singleListener = function() {};
+  chrome.runtime.onSuspend.addListener(singleListener);
+  chrome.runtime.onSuspend.addListener(function() {});
+  chrome.runtime.onSuspend.removeListener(singleListener);
+}
 // No listeners, which previously had listeners (all were removed).
-chrome.runtime.onInstalled.addListener(function() {});
-chrome.runtime.onInstalled.addListener(function() {});
-chrome.runtime.onInstalled.removeListener(function() {});
-chrome.runtime.onInstalled.removeListener(function() {});
+{
+  let listener1 = function() {};
+  let listener2 = function() {};
+  chrome.runtime.onInstalled.addListener(listener1);
+  chrome.runtime.onInstalled.addListener(listener2);
+  chrome.runtime.onInstalled.removeListener(listener1);
+  chrome.runtime.onInstalled.removeListener(listener2);
+}
+
+//
+// Filtered events.
+//
+
+function filterPort(portNumber) {
+  return {url: [{ports: [portNumber]}]};
+}
+
+// A single listener.
+chrome.webNavigation.onBeforeNavigate.addListener(function() {});
+// Multiple, different listeners.
+chrome.webNavigation.onCommitted.addListener(function() {});
+chrome.webNavigation.onCommitted.addListener(function() {});
+// Different listeners with the same filter.
+chrome.webNavigation.onDOMContentLoaded.addListener(
+    function() {}, filterPort(80));
+chrome.webNavigation.onDOMContentLoaded.addListener(
+    function() {}, filterPort(80));
+// Different listeners with different filters, same event added twice.
+{
+  let singleListener = function() {};
+  chrome.webNavigation.onCompleted.addListener(
+      function() {}, filterPort(80));
+  chrome.webNavigation.onCompleted.addListener(
+      function() {}, filterPort(81));
+  chrome.webNavigation.onCompleted.addListener(
+      function() {}, filterPort(81));
+  chrome.webNavigation.onCompleted.addListener(
+      singleListener, filterPort(82));
+  chrome.webNavigation.onCompleted.removeListener(singleListener);
+}
 
 location.assign('page2.html');