Test Location sans browsing context

For whatwg/html#3959 and whatwg/html#4076.

html/browsers/history/the-location-interface/no-browsing-context.window.js

@@ -0,0 +1,86 @@
+test(() => {
+  const frame = document.body.appendChild(document.createElement("iframe")),
+        win = frame.contentWindow,
+        loc = win.location;
+  frame.remove();
+  assert_equals(win.location, loc);
+}, "Window and Location are 1:1 after browsing context removal");
+
+function bcLessLocation() {
+  const frame = document.body.appendChild(document.createElement("iframe")),
+        win = frame.contentWindow,
+        loc = win.location;
+  frame.remove();
+  return loc;
+}
+
+[
+  {
+    "property": "href",
+    "expected": "about:blank",
+    "values": ["https://example.com/", "/", "http://test:test/", "test test", "test:test", "chrome:fail"]
+  },
+  {
+    "property": "protocol",
+    "expected": "about:",
+    "values": ["http", "about", "test"]
+  },
+  {
+    "property": "host",
+    "expected": "",
+    "values": ["example.com", "test test", "()"]
+  },
+  {
+    "property": "hostname",
+    "expected": "",
+    "values": ["example.com"]
+  },
+  {
+    "property": "port",
+    "expected": "",
+    "values": ["80", "", "443", "notaport"]
+  },
+  {
+    "property": "pathname",
+    "expected": "",
+    "values": ["/", "x"]
+  },
+  {
+    "property": "search",
+    "expected": "",
+    "values": ["test"]
+  },
+  {
+    "property": "hash",
+    "expected": "",
+    "values": ["test", "#"]
+  }
+].forEach(testSetup => {
+  testSetup.values.forEach(value => {
+  	test(() => {
+  	  const loc = bcLessLocation();
+  	  loc[testSetup.property] = value;
+  	  assert_equals(loc[testSetup.property], testSetup.expected);
+  	}, "Setting `" + testSetup.property + "` to `" + value + "` of a `Location` object sans browsing context is a no-op");
+  });
+});
+
+test(() => {
+  const loc = bcLessLocation();
+  assert_equals(loc.origin, "null");
+}, "Getting `origin` of a `Location` object sans browsing context should be \"null\"");
+
+["assign", "replace", "reload"].forEach(method => {
+  ["about:blank", "https://example.com/", "/", "http://test:test/", "test test", "test:test", "chrome:fail"].forEach(value => {
+    test(() => {
+      const loc = bcLessLocation();
+      loc[method](value);
+      assert_equals(loc.href, "about:blank");
+    }, "Invoking `" + method + "` with `" + value + "` on a `Location` object sans browsing context is a no-op");
+  });
+});
+
+test(() => {
+  const loc = bcLessLocation();
+  assert_array_equals(loc.ancestorOrigins, []);
+}, "Getting `ancestorOrigins` of a `Location` object sans browsing context should be []");