core(network-request): identify filesystem resources as non-network

lighthouse-core/lib/network-request.js

@@ -480,7 +480,9 @@ class NetworkRequest {
    */
   static isNonNetworkRequest(record) {
     // The 'protocol' field in devtools a string more like a `scheme`
-    return URL.isNonNetworkProtocol(record.protocol);
+    return URL.isNonNetworkProtocol(record.protocol) ||
+      // But `protocol` can fail to be populated if the request fails, so fallback to scheme.
+      URL.isNonNetworkProtocol(record.parsedURL.scheme);
   }
 
   /**

lighthouse-core/lib/url-shim.js

@@ -20,7 +20,7 @@ const allowedProtocols = [
 const SECURE_SCHEMES = ['data', 'https', 'wss', 'blob', 'chrome', 'chrome-extension', 'about',
   'filesystem'];
 const SECURE_LOCALHOST_DOMAINS = ['localhost', '127.0.0.1'];
-const NON_NETWORK_SCHEMES = ['blob', 'data', 'intent'];
+const NON_NETWORK_SCHEMES = ['blob', 'data', 'intent', 'file'];
 
 /**
  * There is fancy URL rewriting logic for the chrome://settings page that we need to work around.

lighthouse-core/test/lib/network-request-test.js

@@ -346,4 +346,23 @@ describe('NetworkRequest', () => {
       })).toBe(true);
     });
   });
+
+  describe('#isNonNetworkRequest', () => {
+    const isNonNetworkRequest = NetworkRequest.isNonNetworkRequest;
+
+    it('correctly identifies non-network records', () => {
+      // data protocol
+      expect(isNonNetworkRequest({protocol: 'data'})).toBe(true);
+
+      // filesystem scheme
+      expect(isNonNetworkRequest({protocol: '', parsedURL: {scheme: 'file'}})).toBe(true);
+    });
+
+    it('correctly identifies network records', () => {
+      expect(isNonNetworkRequest({
+        protocol: 'h2',
+        parsedURL: {scheme: 'http', host: 'google.com'},
+      })).toBe(false);
+    });
+  });
 });