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

extensions/common/url_pattern.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 "extensions/common/url_pattern.h"
 
 #include "base/string_number_conversions.h"
-#include "base/string_piece.h"
 #include "base/string_util.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/common/constants.h"
 #include "googleurl/src/gurl.h"
 #include "googleurl/src/url_util.h"
 
 const char URLPattern::kAllUrlsPattern[] = "<all_urls>";
 
 namespace {
 
@@ skipping 511 matching lines @@
   }
 
   return result;
 }
 
 // static
 const char* URLPattern::GetParseResultString(
     URLPattern::ParseResult parse_result) {
   return kParseResultMessages[parse_result];
 }