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

net/http/http_security_headers_unittest.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.
 
 #include "base/base64.h"
 #include "base/sha1.h"
-#include "base/string_piece.h"
+#include "base/strings/string_piece.h"
 #include "crypto/sha2.h"
 #include "net/base/net_log.h"
 #include "net/base/test_completion_callback.h"
 #include "net/http/http_security_headers.h"
 #include "net/http/http_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 
 namespace {
@@ skipping 399 matching lines @@
 
 TEST_F(HttpSecurityHeadersTest, ValidPinsHeadersSHA1) {
   TestValidPinsHeaders(HASH_VALUE_SHA1);
 }
 
 TEST_F(HttpSecurityHeadersTest, ValidPinsHeadersSHA256) {
   TestValidPinsHeaders(HASH_VALUE_SHA256);
 }
 
 };    // namespace net