fix(event): fix #883, fix RTCPeerConnection Safari event not triggered issue (#905)

Author: JiaLiPassion

gulpfile.js

@@ -137,6 +137,14 @@ gulp.task('build/webapis-notification.min.js', ['compile-esm'], function(cb) {
     return generateScript('./lib/browser/webapis-notification.ts', 'webapis-notification.min.js', true, cb);
 });
 
+gulp.task('build/webapis-rtc-peer-connection.js', ['compile-esm'], function(cb) {
+  return generateScript('./lib/browser/webapis-rtc-peer-connection.ts', 'webapis-rtc-peer-connection.js', false, cb);
+});
+
+gulp.task('build/webapis-rtc-peer-connection.min.js', ['compile-esm'], function(cb) {
+  return generateScript('./lib/browser/webapis-rtc-peer-connection.ts', 'webapis-rtc-peer-connection.min.js', true, cb);
+});
+
 gulp.task('build/webapis-shadydom.js', ['compile-esm'], function(cb) {
     return generateScript('./lib/browser/shadydom.ts', 'webapis-shadydom.js', false, cb);
 });
@@ -245,6 +253,8 @@ gulp.task('build', [
   'build/webapis-media-query.min.js',
   'build/webapis-notification.js',
   'build/webapis-notification.min.js',
+  'build/webapis-rtc-peer-connection.js',
+  'build/webapis-rtc-peer-connection.min.js',
   'build/webapis-shadydom.js',
   'build/webapis-shadydom.min.js',
   'build/zone-patch-cordova.js',

lib/browser/webapis-rtc-peer-connection.ts

@@ -0,0 +1,26 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+Zone.__load_patch('RTCPeerConnection', (global: any, Zone: ZoneType, api: _ZonePrivate) => {
+  const RTCPeerConnection = global['RTCPeerConnection'];
+  if (!RTCPeerConnection) {
+    return;
+  }
+
+  const addSymbol = api.symbol('addEventListener');
+  const removeSymbol = api.symbol('removeEventListener');
+
+  RTCPeerConnection.prototype.addEventListener = RTCPeerConnection.prototype[addSymbol];
+  RTCPeerConnection.prototype.removeEventListener = RTCPeerConnection.prototype[removeSymbol];
+
+  // RTCPeerConnection extends EventTarget, so we must clear the symbol
+  // to allow pathc RTCPeerConnection.prototype.addEventListener again
+  RTCPeerConnection.prototype[addSymbol] = null;
+  RTCPeerConnection.prototype[removeSymbol] = null;
+
+  api.patchEventTarget(global, [RTCPeerConnection.prototype], {useGlobalCallback: false});
+});