Prevent unused-variable warnings in the CrOS build with gcc 4.6.

chrome/browser/chromeos/cros/mount_library.cc

 // Copyright (c) 2011 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/chromeos/cros/mount_library.h"
 
 #include <set>
 #include <sys/statvfs.h>
 #include <vector>
 
@@ skipping 620 matching lines @@
     }
   }
 
   void OnRequestMountInfo(const char** devices,
                           size_t devices_len,
                           MountMethodErrorType error,
                           const char* error_message) {
     std::set<std::string> current_device_set;
     if (error == MOUNT_METHOD_ERROR_NONE && devices && devices_len) {
       // Initiate properties fetch for all removable disks,
-      bool found_disk = false;
       for (size_t i = 0; i < devices_len; i++) {
         if (!devices[i]) {
           NOTREACHED();
           continue;
         }
         current_device_set.insert(std::string(devices[i]));
-        found_disk = true;
         // Initiate disk property retrieval for each relevant device path.
         libcros_proxy_->CallGetDiskProperties(devices[i],
             &GetDiskPropertiesCallback, this);
       }
     } else if (error != MOUNT_METHOD_ERROR_NONE) {
       LOG(WARNING) << "Request mount info retrieval request failed with error: "
                    << (error_message ? error_message : "Unknown");
     }
     // Search and remove disks that are no longer present.
     for (MountLibrary::DiskMap::iterator iter = disks_.begin();
@@ skipping 181 matching lines @@
   MountLibrary* impl;
   if (stub)
     impl = new MountLibraryStubImpl();
   else
     impl = new MountLibraryImpl();
   impl->Init();
   return impl;
 }
 
 }  // namespace chromeos