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

url/url_test_utils.h

 // Copyright 2013 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.
 
 #ifndef URL_URL_TEST_UTILS_H_
 #define URL_URL_TEST_UTILS_H_
 
 // Convenience functions for string conversions.
 // These are mostly intended for use in unit tests.
 
 #include <string>
 
 #include "base/strings/string16.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/url_canon_internal.h"
 
 namespace url_test_utils {
 
 // Converts a UTF-16 string from native wchar_t format to char16, by
 // truncating the high 32 bits.  This is not meant to handle true UTF-32
 // encoded strings.
 inline base::string16 WStringToUTF16(const wchar_t* src) {
   base::string16 str;
   int length = static_cast<int>(wcslen(src));
   for (int i = 0; i < length; ++i) {
-    str.push_back(static_cast<char16>(src[i]));
+    str.push_back(static_cast<base::char16>(src[i]));
   }
   return str;
 }
 
 // Converts a string from UTF-8 to UTF-16
 inline base::string16 ConvertUTF8ToUTF16(const std::string& src) {
   int length = static_cast<int>(src.length());
   EXPECT_LT(length, 1024);
   url_canon::RawCanonOutputW<1024> output;
   EXPECT_TRUE(url_canon::ConvertUTF8ToUTF16(src.data(), length, &output));
   return base::string16(output.data(), output.length());
 }
 
 // Converts a string from UTF-16 to UTF-8
 inline std::string ConvertUTF16ToUTF8(const base::string16& src) {
   std::string str;
   url_canon::StdStringCanonOutput output(&str);
   EXPECT_TRUE(url_canon::ConvertUTF16ToUTF8(src.data(),
                                             static_cast<int>(src.length()),
                                             &output));
   output.Complete();
   return str;
 }
 
 }  // namespace url_test_utils
 
 #endif  // URL_URL_TEST_UTILS_H_