Import //fetch from Web Platform Tests.

third_party/WebKit/LayoutTests/external/wpt/fetch/api/cors/cors-cookies.js

+if (this.document === undefined) {
+  importScripts("/resources/testharness.js");
+  importScripts("../resources/utils.js");
+  importScripts("/common/get-host-info.sub.js")
+}
+
+function corsCookies(desc, baseURL1, baseURL2, credentialsMode, cookies) {
+  var urlSetCookie = baseURL1 + dirname(location.pathname) + RESOURCES_DIR + "top.txt";
+  var urlCheckCookies = baseURL2 + dirname(location.pathname) + RESOURCES_DIR + "inspect-headers.py?cors&headers=cookie";
+  //enable cors with credentials
+  var urlParameters = "?pipe=header(Access-Control-Allow-Origin," + location.origin + ")";
+  urlParameters += "|header(Access-Control-Allow-Credentials,true)";
+
+  var urlCleanParameters = "?pipe=header(Access-Control-Allow-Origin," + location.origin + ")";
+  urlCleanParameters += "|header(Access-Control-Allow-Credentials,true)";
+  if (cookies) {
+    urlParameters += "|header(Set-Cookie,";
+    urlParameters += cookies.join(",True)|header(Set-Cookie,") +  ",True)";
+    urlCleanParameters += "|header(Set-Cookie,";
+    urlCleanParameters +=  cookies.join("%3B%20max-age=0,True)|header(Set-Cookie,") +  "%3B%20max-age=0,True)";
+  }
+
+  var requestInit = {"credentials": credentialsMode, "mode": "cors"};
+
+  promise_test(function(test){
+    return fetch(urlSetCookie + urlParameters, requestInit).then(function(resp) {
+      assert_equals(resp.status, 200, "HTTP status is 200");
+      //check cookies sent
+      return fetch(urlCheckCookies, requestInit);
+    }).then(function(resp) {
+      assert_equals(resp.status, 200, "HTTP status is 200");
+      assert_false(resp.headers.has("Cookie") , "Cookie header is not exposed in response");
+      if (credentialsMode === "include" && baseURL1 === baseURL2) {
+        assert_equals(resp.headers.get("x-request-cookie") , cookies.join("; "), "Request includes cookie(s)");
+      }
+      else {
+        assert_false(resp.headers.has("x-request-cookie") , "Request should have no cookie");
+      }
+      //clean cookies
+      return fetch(urlSetCookie + urlCleanParameters, {"credentials": "include"});
+    }).catch(function(e) {
+      return fetch(urlSetCookie + urlCleanParameters, {"credentials": "include"}).then(function(resp) {
+        throw e;
+      })
+    });
+  }, desc);
+}
+
+var local = get_host_info().HTTP_ORIGIN;
+var remote = get_host_info().HTTP_REMOTE_ORIGIN;
+// FIXME: otherRemote might not be accessible on some test environments.
+var otherRemote = local.replace("http://", "http://www.");
+
+corsCookies("Omit mode: no cookie sent", local, local, "omit", ["g=7"]);
+corsCookies("Include mode: 1 cookie", remote, remote, "include", ["a=1"]);
+corsCookies("Include mode: local cookies are not sent with remote request", local, remote, "include", ["c=3"]);
+corsCookies("Include mode: remote cookies are not sent with local request", remote, local, "include", ["d=4"]);
+corsCookies("Same-origin mode: cookies are discarded in cors request", remote, remote, "same-origin", ["f=6"]);
+corsCookies("Include mode: remote cookies are not sent with other remote request", remote, otherRemote, "include", ["e=5"]);
+
+done();