[V8] Run clang-tidy performance-for-range-copy check on src/

src/libplatform/tracing/trace-config.cc

 // Copyright 2016 the V8 project 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 <string.h>
 
 #include "include/libplatform/v8-tracing.h"
 #include "src/base/logging.h"
 
 namespace v8 {
 
 class Isolate;
 
 namespace platform {
 namespace tracing {
 
 TraceConfig* TraceConfig::CreateDefaultTraceConfig() {
   TraceConfig* trace_config = new TraceConfig();
   trace_config->included_categories_.push_back("v8");
   return trace_config;
 }
 
 bool TraceConfig::IsCategoryGroupEnabled(const char* category_group) const {
   std::stringstream category_stream(category_group);
   while (category_stream.good()) {
     std::string category;
     getline(category_stream, category, ',');
-    for (auto included_category : included_categories_) {
+    for (const auto& included_category : included_categories_) {
       if (category == included_category) return true;
     }
   }
   return false;
 }
 
 void TraceConfig::AddIncludedCategory(const char* included_category) {
   DCHECK(included_category != NULL && strlen(included_category) > 0);
   included_categories_.push_back(included_category);
 }
 
 }  // namespace tracing
 }  // namespace platform
 }  // namespace v8