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

This change adds the necessary plumbing for the USB Mojo service
implementation to detect when a device is already open and to report
this error so that the WebUSB API can reject the promise returned by
USBDevice::open() with an InvalidStateError.

BUG=492204

Review URL: https://codereview.chromium.org/1693433003

Cr-Commit-Position: refs/heads/master@{#375003}

1 files changed, 13 insertions, 4 deletions

diff --git a/device/usb/mojo/device_impl_unittest.cc b/device/usb/mojo/device_impl_unittest.cc
index 626edd9..c6c2e49 100644
--- a/device/usb/mojo/device_impl_unittest.cc
+++ b/device/usb/mojo/device_impl_unittest.cc
@@ -459,10 +459,19 @@ TEST_F(USBDeviceImplTest, 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());
 }