feat(Request): allow aborting intercepted requests with custom reasons (#1080)

This patch adds optional parameter to the `request.abort()` method
that specifies abort reason.

References #1020.

lib/NetworkManager.js

@@ -340,16 +340,21 @@ class Request {
     });
   }
 
-  async abort() {
+  /**
+   * @param {string=} errorCode
+   */
+  async abort(errorCode = 'failed') {
     // DataURL's are not interceptable. In this case, do nothing.
     if (this.url.startsWith('data:'))
       return;
+    const errorReason = errorReasons[errorCode];
+    console.assert(errorReason, 'Unknown error code: ' + errorCode);
     console.assert(this._allowInterception, 'Request Interception is not enabled!');
     console.assert(!this._interceptionHandled, 'Request is already handled!');
     this._interceptionHandled = true;
     await this._client.send('Network.continueInterceptedRequest', {
       interceptionId: this._interceptionId,
-      errorReason: 'Failed'
+      errorReason
     }).catch(error => {
       // In certain cases, protocol will return error if the request was already canceled
       // or the page was closed. We should tolerate these errors.
@@ -357,6 +362,22 @@ class Request {
     });
   }
 }
+
+const errorReasons = {
+  'aborted': 'Aborted',
+  'accessdenied': 'AccessDenied',
+  'addressunreachable': 'AddressUnreachable',
+  'connectionaborted': 'ConnectionAborted',
+  'connectionclosed': 'ConnectionClosed',
+  'connectionfailed': 'ConnectionFailed',
+  'connectionrefused': 'ConnectionRefused',
+  'connectionreset': 'ConnectionReset',
+  'internetdisconnected': 'InternetDisconnected',
+  'namenotresolved': 'NameNotResolved',
+  'timedout': 'TimedOut',
+  'failed': 'Failed',
+};
+
 helper.tracePublicAPI(Request);
 
 class Response {