Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/storage_monitor/volume_mount_watcher_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/storage_monitor/volume_mount_watcher_win.h"
 
 #include <windows.h>
 
 #include <dbt.h>
 #include <fileapi.h>
@@ skipping 130 matching lines @@
                                         kMaxPathBufLen)) {
     return false;
   }
 
   // If we're adding a floppy drive, return without querying any more
   // drive metadata -- it will cause the floppy drive to seek.
   // Note: treats FLOPPY as FIXED_MASS_STORAGE. This is intentional.
   DeviceType device_type = GetDeviceType(mount_point);
   if (device_type == FLOPPY) {
     info->set_device_id(StorageInfo::MakeDeviceId(
-        StorageInfo::FIXED_MASS_STORAGE, UTF16ToUTF8(guid)));
+        StorageInfo::FIXED_MASS_STORAGE, base::UTF16ToUTF8(guid)));
     return true;
   }
 
   StorageInfo::Type type = StorageInfo::FIXED_MASS_STORAGE;
   if (device_type == REMOVABLE) {
     type = StorageInfo::REMOVABLE_MASS_STORAGE_NO_DCIM;
     if (MediaStorageUtil::HasDcim(base::FilePath(mount_point)))
       type = StorageInfo::REMOVABLE_MASS_STORAGE_WITH_DCIM;
   }
 
   // NOTE: experimentally, this function returns false if there is no volume
   // name set.
   base::string16 volume_label;
   GetVolumeInformationW(device_path.value().c_str(),
                         WriteInto(&volume_label, kMaxPathBufLen),
                         kMaxPathBufLen, NULL, NULL, NULL, NULL, 0);
 
   uint64 total_size_in_bytes = GetVolumeSize(mount_point);
-  std::string device_id = StorageInfo::MakeDeviceId(type, UTF16ToUTF8(guid));
+  std::string device_id =
+      StorageInfo::MakeDeviceId(type, base::UTF16ToUTF8(guid));
 
   // TODO(gbillock): if volume_label.empty(), get the vendor/model information
   // for the volume.
   *info = StorageInfo(device_id, base::string16(), mount_point,
                       volume_label, base::string16(), base::string16(),
                       total_size_in_bytes);
   return true;
 }
 
 // Returns a vector of all the removable mass storage devices that are
@@ skipping 337 matching lines @@
   }
   if (device_metadata_.erase(device) == 0) {
     callback.Run(StorageMonitor::EJECT_FAILURE);
     return;
   }
 
   task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&EjectDeviceInThreadPool, device, callback, task_runner_, 0));
 }