Update some uses of char16 to use the base:: namespace.

chrome/browser/storage_monitor/storage_monitor_mac.mm

 // 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/storage_monitor_mac.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 14 matching lines @@
     return base::string16();
   return base::SysCFStringRefToUTF16(value);
 }
 
 base::string16 JoinName(const base::string16& name,
                         const base::string16& addition) {
   if (addition.empty())
     return name;
   if (name.empty())
     return addition;
-  return name + static_cast<char16>(' ') + addition;
+  return name + static_cast<base::char16>(' ') + addition;
 }
 
 StorageInfo::Type GetDeviceType(bool is_removable, bool has_dcim) {
   if (!is_removable)
     return StorageInfo::FIXED_MASS_STORAGE;
   if (has_dcim)
     return StorageInfo::REMOVABLE_MASS_STORAGE_WITH_DCIM;
   return StorageInfo::REMOVABLE_MASS_STORAGE_NO_DCIM;
 }
 
@@ skipping 332 matching lines @@
       *info = it->second;
       return true;
     }
   }
   return false;
 }
 
 StorageMonitor* StorageMonitor::Create() {
   return new StorageMonitorMac();
 }