Move string_piece.h to base/strings.

base/strings/string_piece.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.
 // Copied from strings/stringpiece.cc with modifications
 
+#include "base/strings/string_piece.h"
+
 #include <algorithm>
 #include <ostream>
 
-#include "base/string_piece.h"
-
 namespace base {
 
 // MSVC doesn't like complex extern templates and DLLs.
 #if !defined(COMPILER_MSVC)
 namespace internal {
 template class StringPieceDetail<std::string>;
 template class StringPieceDetail<string16>;
 }  // namespace internal
 
 template class BasicStringPiece<string16>;
@@ skipping 225 matching lines @@
 StringPiece substr(const StringPiece& self,
                    StringPiece::size_type pos,
                    StringPiece::size_type n) {
   if (pos > self.size()) pos = self.size();
   if (n > self.size() - pos) n = self.size() - pos;
   return StringPiece(self.data() + pos, n);
 }
 
 }  // namespace internal
 }  // namespace base