Partially implement WorkerFetchContext and WorkerThreadableLoadingContext and add virtual tests

third_party/WebKit/LayoutTests/virtual/off-main-thread-fetch/http/tests/xmlhttprequest/workers/cross-origin-unsupported-url-expected.txt

Index: third_party/WebKit/LayoutTests/virtual/off-main-thread-fetch/http/tests/xmlhttprequest/workers/cross-origin-unsupported-url-expected.txt
diff --git a/third_party/WebKit/LayoutTests/virtual/off-main-thread-fetch/http/tests/xmlhttprequest/workers/cross-origin-unsupported-url-expected.txt b/third_party/WebKit/LayoutTests/virtual/off-main-thread-fetch/http/tests/xmlhttprequest/workers/cross-origin-unsupported-url-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..de5a621f39fca2a73f990d753eb7dfe91e6203f4
--- /dev/null
+++ b/third_party/WebKit/LayoutTests/virtual/off-main-thread-fetch/http/tests/xmlhttprequest/workers/cross-origin-unsupported-url-expected.txt
@@ -0,0 +1,40 @@
+CONSOLE ERROR: line 20: XMLHttpRequest cannot load ftp://127.0.0.1/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 1: XMLHttpRequest cannot load ftp://127.0.0.1/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 20: XMLHttpRequest cannot load ftp://127.0.0.1/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 1: XMLHttpRequest cannot load ftp://127.0.0.1/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 20: XMLHttpRequest cannot load localhost:8080/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 1: XMLHttpRequest cannot load localhost:8080/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 20: XMLHttpRequest cannot load localhost:8080/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 1: XMLHttpRequest cannot load localhost:8080/. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 20: XMLHttpRequest cannot load tel:1234. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 1: XMLHttpRequest cannot load tel:1234. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 20: XMLHttpRequest cannot load tel:1234. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+CONSOLE ERROR: line 1: XMLHttpRequest cannot load tel:1234. Cross origin requests are only supported for protocol schemes: http, data, chrome, https.
+[Worker] Test cross-origin XHRs to CORS-unsupported protocol schemes in the URL.
+
+On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".
+
+
+Starting worker: ../resources/cross-origin-unsupported-url.js
+PASS [Worker] errorEvent.name is "NetworkError"
+PASS [Worker] errorEvent.type is "error"
+PASS [Worker] xhr.send() did not throw exception.
+PASS [Worker] errorEvent.name is "NetworkError"
+PASS [Worker] errorEvent.type is "error"
+PASS [Worker] xhr.send() did not throw exception.
+PASS [Worker] errorEvent.name is "NetworkError"
+PASS [Worker] errorEvent.type is "error"
+PASS [Worker] xhr.send() did not throw exception.
+PASS [Worker] errorEvent.name is "NetworkError"
+PASS [Worker] errorEvent.type is "error"
+PASS [Worker] xhr.send() did not throw exception.
+PASS [Worker] errorEvent.name is "NetworkError"
+PASS [Worker] errorEvent.type is "error"
+PASS [Worker] xhr.send() did not throw exception.
+PASS [Worker] errorEvent.name is "NetworkError"
+PASS [Worker] errorEvent.type is "error"
+PASS [Worker] xhr.send() did not throw exception.
+PASS successfullyParsed is true
+
+TEST COMPLETE
+