Fix testharness result parsing, make "Harness error" count as failure.

third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch-expected.txt

+This is a testharness.js-based test.
+Harness Error. harness_status.status = 1 , harness_status.message = 1 duplicate test name: "Simple Fetch"
+PASS Body ignored in presence of a PasswordCredential 
+PASS Body present if 'credentials' is not a PasswordCredential 
+PASS Creating/cloning a 'Request' does not expose the credential. 
+PASS Creating a 'Request' throws in various ways. 
+PASS Simple Fetch 
+PASS Simple Fetch 
+PASS Fetch with cloned Request 
+PASS Fetch with copied Request 
+PASS Fetch with overridden 'credentials' 
+PASS 'idName' and 'passwordName' 
+PASS 'additionalData': Empty FormData has no effect. 
+PASS 'additionalData': FormData properties are properly injected. 
+PASS 'additionalData': FormData properties are properly injected after assignment. 
+PASS 'additionalData': FormData properties are properly overridden. 
+PASS 'additionalData': Empty URLSearchParams has no effect. 
+PASS 'additionalData': URLSearchParams properties are properly injected. 
+PASS 'additionalData': URLSearchParams properties are properly overridden. 
+PASS 'additionalData': URLSearchParams properties are properly injected (ordering matters). 
+PASS fetch() after get() 
+PASS fetch() after get() with additionalData 
+PASS fetch() after get() with additionalData from DOM 
+Harness: the test ran to completion.
+