Add an SD card reader test.

client/site_tests/hardware_RealtekCardReader/hardware_RealtekCardReader.py

Index: client/site_tests/hardware_RealtekCardReader/hardware_RealtekCardReader.py
diff --git a/client/site_tests/hardware_RealtekCardReader/hardware_RealtekCardReader.py b/client/site_tests/hardware_RealtekCardReader/hardware_RealtekCardReader.py
new file mode 100644
index 0000000000000000000000000000000000000000..e710f05d38104dabb0bb4152ddf7feb2681e1de7
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+++ b/client/site_tests/hardware_RealtekCardReader/hardware_RealtekCardReader.py
@@ -0,0 +1,30 @@
+# Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import glob, logging, os
+
+from autotest_lib.client.bin import test, utils
+from autotest_lib.client.common_lib import error
+
+class hardware_RealtekCardReader(test.test):
+    version = 1
+
+    def run_once(self):
+        # Look for the Realtek USB card reader.
+        # This requires a plugged in SD card.
+        lsusb_output = utils.system_output("lsusb")
+        if not "0bda:0138 Realtek" in lsusb_output:
+            raise error.TestFail("The Realtek card reader USB device was not "
+                                 "detected.  This test requires an SD card to "
+                                 "be inserted to detect the USB device.")
+
+        blockdevs = glob.glob("/sys/block/*")
+        for dev in blockdevs:
+            removable = utils.read_one_line(os.path.join(dev, "removable"))
+            if removable == "1":
+                logging.info("Found removable block device %s", dev)
+                return True
+
+        raise error.TestFail("The card reader USB device was detected, but "
+                             "no removable block devices are seen.")