Revert of Move JoinString to the base namespace

extensions/browser/updater/manifest_fetch_data.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 "extensions/browser/updater/manifest_fetch_data.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ skipping 125 matching lines @@
           ping_value += "&";
         ping_value += "a=" + base::IntToString(ping_data->active_days);
         pings_[id].active_days = ping_data->active_days;
       }
     }
     if (!ping_value.empty())
       parts.push_back("ping=" + net::EscapeQueryParamValue(ping_value, true));
   }
 
   std::string extra = full_url_.has_query() ? "&" : "?";
-  extra +=
-      "x=" + net::EscapeQueryParamValue(base::JoinString(parts, "&"), true);
+  extra += "x=" + net::EscapeQueryParamValue(JoinString(parts, '&'), true);
 
   // Check against our max url size, exempting the first extension added.
   int new_size = full_url_.possibly_invalid_spec().size() + extra.size();
   if (!extension_ids_.empty() && new_size > kExtensionsManifestMaxURLSize) {
     UMA_HISTOGRAM_PERCENTAGE("Extensions.UpdateCheckHitUrlSizeLimit", 1);
     return false;
   }
   UMA_HISTOGRAM_PERCENTAGE("Extensions.UpdateCheckHitUrlSizeLimit", 0);
 
   // We have room so go ahead and add the extension.
@@ skipping 24 matching lines @@
 void ManifestFetchData::Merge(const ManifestFetchData& other) {
   DCHECK(full_url() == other.full_url());
   request_ids_.insert(other.request_ids_.begin(), other.request_ids_.end());
 }
 
 bool ManifestFetchData::DidForceUpdate(const std::string& extension_id) const {
   return forced_updates_.find(extension_id) != forced_updates_.end();
 }
 
 }  // namespace extensions