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

third_party/WebKit/LayoutTests/http/tests/fetch/serviceworker/response-base-https-other-https-expected.txt

+This is a testharness.js-based test.
+Harness Error. harness_status.status = 1 , harness_status.message = 1 duplicate test name: "Response constructed with a stream"
+PASS Startup 
+PASS response 
+PASS Response default value test 
+PASS Construct a Response with null body using undefined. 
+PASS Construct a Response with null body using null. 
+PASS Response constructor test 
+PASS Response content type test 
+PASS Response throw error test 
+PASS Cancel body stream on Response 
+PASS call text() on null body response 
+PASS call arrayBuffer() on null body response 
+PASS call blob() on null body response 
+PASS call json() on null body response 
+PASS Clone on Response (text) 
+PASS Clone on Response (manual read) 
+PASS Used => clone 
+PASS Locked => clone 
+PASS MIME type for Blob 
+PASS MIME type for Blob with non-empty type 
+PASS MIME type for FormData 
+PASS MIME type for USVString 
+PASS Extract a MIME type with clone 
+PASS MIME type unchanged if headers are modified after Response() constructor 
+PASS Extract a MIME type (1) 
+PASS Response.error() 
+PASS Response.redirect() with default status value 
+PASS Response.redirect() with 301 
+PASS Response.redirect() with URLs with CR or LF 
+PASS Response constructed with a stream 
+PASS Response constructed with a stream 
+PASS Response constructed with a String / Read from body stream 
+PASS Response constructed with a stream / Read from body stream 
+PASS Response constructed with an errored stream 
+PASS Response constructed with a locked stream 
+PASS Response constructed stream with an undefined chunk 
+PASS Response constructed stream with a null chunk 
+PASS Response constructed stream with a string chunk 
+Harness: the test ran to completion.
+