Current Serial port pattern in source cannot find proper port name.

chrome/browser/extensions/api/serial/serial_port_enumerator_win.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/api/serial/serial_port_enumerator.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 
@@ skipping 26 matching lines @@
 // static
 SerialPortEnumerator::StringSet
 SerialPortEnumerator::GenerateValidSerialPortNames() {
   StringSet name_set;
   int max_port_number = 16;
 
   // We ended up not using valid_patterns. TODO(miket): we might want
   // to refactor this interface to make it more platform-independent.
   for (int port_number = 0; port_number < max_port_number; ++port_number) {
     string16 device_string16;
-    device_string16 = base::StringPrintf(L"\\\\.\\COM%d", port_number);
+    device_string16 = base::StringPrintf(L"COM%d", port_number);
     if (PassesCommConfigTest(device_string16)) {
       // Keep looking for new ports as long as we're finding them.
       int new_max_port_number = (port_number + 1) * 2;
       if (new_max_port_number > max_port_number)
         max_port_number = new_max_port_number;
 
       std::string device_string(WideToASCII(device_string16));
       name_set.insert(device_string);
     }
   }
   return name_set;
 }
 
 }  // namespace extensions