feat(Chromium): roll Chromium to r518818 (puppeteer#1455)

This roll includes:
- crrev.com/518362 DevTools: override referrer policy for the request if
  referer header is overriden

Fixes puppeteer#1373.

lib/NetworkManager.js

@@ -147,10 +147,10 @@ class NetworkManager extends EventEmitter {
       }).catch(debugError);
     }
 
-    if (event.redirectStatusCode) {
+    if (event.redirectUrl) {
       const request = this._interceptionIdToRequest.get(event.interceptionId);
       console.assert(request, 'INTERNAL ERROR: failed to find request for interception redirect.');
-      this._handleRequestRedirect(request, event.redirectStatusCode, event.redirectHeaders);
+      this._handleRequestRedirect(request, event.responseStatusCode, event.responseHeaders);
       this._handleRequestStart(request._requestId, event.interceptionId, event.redirectUrl, event.resourceType, event.request);
       return;
     }

package.json

@@ -34,7 +34,7 @@
     "ws": "^3.0.0"
   },
   "puppeteer": {
-    "chromium_revision": "515411"
+    "chromium_revision": "518818"
   },
   "devDependencies": {
     "@types/debug": "0.0.30",