base: Update the include paths of base/string_piece.h to its new location.

base/utf_string_conversions_unittest.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 "base/basictypes.h"
 #include "base/logging.h"
-#include "base/string_piece.h"
 #include "base/string_util.h"
+#include "base/strings/string_piece.h"
 #include "base/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
 namespace {
 
 const wchar_t* const kConvertRoundtripCases[] = {
   L"Google Video",
   // "网页 图片 资讯更多 »"
@@ skipping 183 matching lines @@
   EXPECT_EQ(arraysize(wmulti) - 1, wmultistring.length());
   std::string expected;
   memcpy(WriteInto(&expected, arraysize(multi)), multi, sizeof(multi));
   EXPECT_EQ(arraysize(multi) - 1, expected.length());
   const std::string& converted = WideToUTF8(wmultistring);
   EXPECT_EQ(arraysize(multi) - 1, converted.length());
   EXPECT_EQ(expected, converted);
 }
 
 }  // base