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

base/debug/crash_logging.h

 // 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.
 
 #ifndef BASE_DEBUG_CRASH_LOGGING_H_
 #define BASE_DEBUG_CRASH_LOGGING_H_
 
 #include <string>
 #include <vector>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 
 // These functions add metadata to the upload payload when sending crash reports
 // to the crash server.
 //
 // IMPORTANT: On OS X and Linux, the key/value pairs are only sent as part of
 // the upload and are not included in the minidump!
 
 namespace base {
 namespace debug {
 
@@ skipping 68 matching lines @@
     const base::StringPiece& value,
     size_t chunk_max_length);
 
 // Resets the crash key system so it can be reinitialized. For testing only.
 BASE_EXPORT void ResetCrashLoggingForTesting();
 
 }  // namespace debug
 }  // namespace base
 
 #endif  // BASE_DEBUG_CRASH_LOGGING_H_