Migrate WebUSB LayoutTests into external/wpt

third_party/WebKit/LayoutTests/external/wpt/webusb/resources/usb-helpers.js

+'use strict';
+
+function usb_test(func, name, properties) {
+  promise_test(() => {
+    return navigator.usb.test.initialize().then(() => {
+      let testResult = func();
+      let cleanup = () => {
+        navigator.usb.test.reset();
+      };
+      testResult.then(cleanup, cleanup);
+      return testResult;
+    });
+  }, name, properties);
+}
+
+function assertRejectsWithError(promise, name, message) {
+  return promise.then(() => {
+    assert_unreached('expected promise to reject with ' + name);
+  }, error => {
+    assert_equals(error.name, name);
+    if (message !== undefined)
+      assert_equals(error.message, message);
+  });
+}
+
+function assertDeviceInfoEquals(usbDevice, deviceInit) {
+  for (var property in deviceInit) {
+    if (property == 'activeConfigurationValue') {
+      if (deviceInit.activeConfigurationValue == 0) {
+        assert_equals(usbDevice.configuration, null);
+      } else {
+        assert_equals(usbDevice.configuration.configurationValue,
+                      deviceInit.activeConfigurationValue);
+      }
+    } else if (Array.isArray(deviceInit[property])) {
+      assert_equals(usbDevice[property].length, deviceInit[property].length);
+      for (var i = 0; i < usbDevice[property].length; ++i)
+        assertDeviceInfoEquals(usbDevice[property][i], deviceInit[property][i]);
+    } else {
+      assert_equals(usbDevice[property], deviceInit[property], property);
+    }
+  }
+}
+
+function callWithTrustedClick(callback) {
+  return new Promise(resolve => {
+    let button = document.createElement('button');
+    button.textContent = 'click to continue test';
+    button.style.display = 'block';
+    button.style.fontSize = '20px';
+    button.style.padding = '10px';
+    button.onclick = () => {
+      resolve(callback());
+      document.body.removeChild(button);
+    };
+    document.body.appendChild(button);
+  });
+}