webusb: Reject the promise if the device is already open.

device/usb/mojo/device_impl_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "device/usb/mojo/device_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
@@ skipping 441 matching lines @@
 
 }  // namespace
 
 TEST_F(USBDeviceImplTest, Open) {
   DevicePtr device = GetMockDeviceProxy();
 
   EXPECT_FALSE(is_device_open());
 
   EXPECT_CALL(mock_device(), Open(_));
 
-  base::RunLoop loop;
-  device->Open(
-      base::Bind(&ExpectOpenAndThen, OpenDeviceError::OK, loop.QuitClosure()));
-  loop.Run();
+  {
+    base::RunLoop loop;
+    device->Open(base::Bind(&ExpectOpenAndThen, OpenDeviceError::OK,
+                            loop.QuitClosure()));
+    loop.Run();
+  }
+
+  {
+    base::RunLoop loop;
+    device->Open(base::Bind(&ExpectOpenAndThen, OpenDeviceError::ALREADY_OPEN,
+                            loop.QuitClosure()));
+    loop.Run();
+  }
 
   EXPECT_CALL(mock_handle(), Close());
 }
 
 TEST_F(USBDeviceImplTest, Close) {
   DevicePtr device = GetMockDeviceProxy();
 
   EXPECT_FALSE(is_device_open());
 
   EXPECT_CALL(mock_device(), Open(_));
@@ skipping 410 matching lines @@
         base::Bind(&ExpectPacketsInAndThen, fake_inbound_data,
                    expected_transferred_lengths, loop.QuitClosure()));
     loop.Run();
   }
 
   EXPECT_CALL(mock_handle(), Close());
 }
 
 }  // namespace usb
 }  // namespace device