Use StringPiece for UTF string conversions.

ui/base/clipboard/clipboard_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.
 
 // Many of these functions are based on those found in
 // webkit/port/platform/PasteboardWin.cpp
 
 #include "ui/base/clipboard/clipboard.h"
 
 #include <shlobj.h>
@@ skipping 209 matching lines @@
 
   ::EmptyClipboard();
 
   for (ObjectMap::const_iterator iter = objects.begin();
        iter != objects.end(); ++iter) {
     DispatchObject(static_cast<ObjectType>(iter->first), iter->second);
   }
 }
 
 void Clipboard::WriteText(const char* text_data, size_t text_len) {
-  string16 text;
-  UTF8ToUTF16(text_data, text_len, &text);
+  base::string16 text =
+      base::UTF8ToUTF16(base::StringPiece(text_data, text_len));
   HGLOBAL glob = CreateGlobalData(text);
 
   WriteToClipboard(CF_UNICODETEXT, glob);
 }
 
 void Clipboard::WriteHTML(const char* markup_data,
                           size_t markup_len,
                           const char* url_data,
                           size_t url_len) {
   std::string markup(markup_data, markup_len);
@@ skipping 583 matching lines @@
   if (!clipboard_owner_)
     return NULL;
 
   if (clipboard_owner_->hwnd() == NULL)
     clipboard_owner_->Create(base::Bind(&ClipboardOwnerWndProc));
 
   return clipboard_owner_->hwnd();
 }
 
 }  // namespace ui