Cleanup: Remove some unneeded string allocations.

components/search_engines/template_url_parser.cc

 // Copyright 2014 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 "components/search_engines/template_url_parser.h"
 
 #include <algorithm>
 #include <map>
 #include <vector>
 
@@ skipping 273 matching lines @@
   }
   context->string_.clear();
   context->elements_.pop_back();
 }
 
 // static
 void TemplateURLParsingContext::CharactersImpl(void* ctx,
                                                const xmlChar* ch,
                                                int len) {
   reinterpret_cast<TemplateURLParsingContext*>(ctx)->string_ +=
-      base::UTF8ToUTF16(std::string(reinterpret_cast<const char*>(ch), len));
+      base::UTF8ToUTF16(
+          base::StringPiece(reinterpret_cast<const char*>(ch), len));
 }
 
 TemplateURL* TemplateURLParsingContext::GetTemplateURL(
     const SearchTermsData& search_terms_data,
     bool show_in_default_list) {
   // TODO(jcampan): Support engines that use POST; see http://crbug.com/18107
   if (method_ == TemplateURLParsingContext::POST || data_.short_name.empty() ||
       !IsHTTPRef(data_.url()) || !IsHTTPRef(data_.suggestions_url))
     return NULL;
   if (suggestion_method_ == TemplateURLParsingContext::POST)
@@ skipping 196 matching lines @@
   sax_handler.startElement = &TemplateURLParsingContext::StartElementImpl;
   sax_handler.endElement = &TemplateURLParsingContext::EndElementImpl;
   sax_handler.characters = &TemplateURLParsingContext::CharactersImpl;
   int error = xmlSAXUserParseMemory(&sax_handler, &context, data,
                                     static_cast<int>(length));
   xmlSubstituteEntitiesDefault(last_sub_entities_value);
 
   return error ?
       NULL : context.GetTemplateURL(search_terms_data, show_in_default_list);
 }