Revert of Move JoinString to the base namespace

base/trace_event/trace_event_impl.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/trace_event/trace_event_impl.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/base_switches.h"
@@ skipping 2334 matching lines @@
   if (process_labels_.size() > 0) {
     std::vector<std::string> labels;
     for(base::hash_map<int, std::string>::iterator it = process_labels_.begin();
         it != process_labels_.end();
         it++) {
       labels.push_back(it->second);
     }
     InitializeMetadataEvent(AddEventToThreadSharedChunkWhileLocked(NULL, false),
                             current_thread_id,
                             "process_labels", "labels",
-                            base::JoinString(labels, ","));
+                            JoinString(labels, ','));
   }
 
   // Thread sort indices.
   for(hash_map<int, int>::iterator it = thread_sort_indices_.begin();
       it != thread_sort_indices_.end();
       it++) {
     if (it->second == 0)
       continue;
     InitializeMetadataEvent(AddEventToThreadSharedChunkWhileLocked(NULL, false),
                             it->first,
@@ skipping 154 matching lines @@
 }
 
 ScopedTraceBinaryEfficient::~ScopedTraceBinaryEfficient() {
   if (*category_group_enabled_) {
     TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(category_group_enabled_,
                                                 name_, event_handle_);
   }
 }
 
 }  // namespace trace_event_internal