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

base/string_util.h

 // Copyright (c) 2011 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.
 //
 // This file defines utility functions for working with strings.
 
 #ifndef BASE_STRING_UTIL_H_
 #define BASE_STRING_UTIL_H_
 
 #include <ctype.h>
 #include <stdarg.h>   // va_list
 
 #include <string>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/string16.h"
-#include "base/string_piece.h"  // For implicit conversions.
+#include "base/strings/string_piece.h"  // For implicit conversions.
 
 // Safe standard library wrappers for all platforms.
 
 namespace base {
 
 // C standard-library functions like "strncasecmp" and "snprintf" that aren't
 // cross-platform are provided as "base::strncasecmp", and their prototypes
 // are listed below.  These functions are then implemented as inline calls
 // to the platform-specific equivalents in the platform-specific headers.
 
@@ skipping 536 matching lines @@
 #elif defined(WCHAR_T_IS_UTF32)
   typedef uint32 Unsigned;
 #endif
 };
 template<>
 struct ToUnsigned<short> {
   typedef unsigned short Unsigned;
 };
 
 #endif  // BASE_STRING_UTIL_H_