Move ASCIIToWide and ASCIIToUTF16 to utf_string_conversions.h. I've found it...

net/spdy/spdy_session.cc

 // Copyright (c) 2010 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 "net/spdy/spdy_session.h"
 
 #include "base/basictypes.h"
 #include "base/linked_ptr.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/rand_util.h"
 #include "base/stats_counters.h"
 #include "base/stl_util-inl.h"
 #include "base/string_util.h"
+#include "base/utf_string_conversions.h"
 #include "base/time.h"
 #include "base/values.h"
 #include "net/base/connection_type_histograms.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_log.h"
 #include "net/base/net_util.h"
 #include "net/http/http_network_session.h"
 #include "net/socket/client_socket.h"
 #include "net/socket/client_socket_factory.h"
 #include "net/socket/ssl_client_socket.h"
@@ skipping 1303 matching lines @@
           UMA_HISTOGRAM_CUSTOM_COUNTS("Net.SpdySettingsRetransRate",
                                       setting.second,
                                       1, 100, 50);
           break;
       }
     }
   }
 }
 
 }  // namespace net