Use interface associations to check function permissions.

device/usb/usb_device_handle_unittest.cc

Index: device/usb/usb_device_handle_unittest.cc
diff --git a/device/usb/usb_device_handle_unittest.cc b/device/usb/usb_device_handle_unittest.cc
index 5fac40a55e7c82ef090fb22e2ae54a2e5834bf9d..84072dcddca0ab9e44f99d6afdbd546fd1d0969d 100644
--- a/device/usb/usb_device_handle_unittest.cc
+++ b/device/usb/usb_device_handle_unittest.cc
@@ -132,6 +132,16 @@ TEST_F(UsbDeviceHandleTest, InterruptTransfer) {
   handle->ClaimInterface(0, claim_interface.callback());
   ASSERT_TRUE(claim_interface.WaitForResult());
 
+  const UsbInterfaceDescriptor* interface =
+      handle->FindInterfaceByEndpoint(0x81);
+  EXPECT_TRUE(interface);
+  EXPECT_EQ(0, interface->interface_number);
+  interface = handle->FindInterfaceByEndpoint(0x01);
+  EXPECT_TRUE(interface);
+  EXPECT_EQ(0, interface->interface_number);
+  EXPECT_FALSE(handle->FindInterfaceByEndpoint(0x82));
+  EXPECT_FALSE(handle->FindInterfaceByEndpoint(0x02));
+
   scoped_refptr<net::IOBufferWithSize> in_buffer(new net::IOBufferWithSize(64));
   TestCompletionCallback in_completion;
   handle->GenericTransfer(USB_DIRECTION_INBOUND, 0x81, in_buffer.get(),
@@ -190,6 +200,16 @@ TEST_F(UsbDeviceHandleTest, BulkTransfer) {
   handle->ClaimInterface(1, claim_interface.callback());
   ASSERT_TRUE(claim_interface.WaitForResult());
 
+  EXPECT_FALSE(handle->FindInterfaceByEndpoint(0x81));
+  EXPECT_FALSE(handle->FindInterfaceByEndpoint(0x01));
+  const UsbInterfaceDescriptor* interface =
+      handle->FindInterfaceByEndpoint(0x82);
+  EXPECT_TRUE(interface);
+  EXPECT_EQ(1, interface->interface_number);
+  interface = handle->FindInterfaceByEndpoint(0x02);
+  EXPECT_TRUE(interface);
+  EXPECT_EQ(1, interface->interface_number);
+
   scoped_refptr<net::IOBufferWithSize> in_buffer(
       new net::IOBufferWithSize(512));
   TestCompletionCallback in_completion;