Use StringPiece for CreateUploader/NetMetricsLogUploader params.

components/metrics/net/net_metrics_log_uploader.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/metrics/net/net_metrics_log_uploader.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/metrics/metrics_log_uploader.h"
 #include "net/base/load_flags.h"
 #include "net/url_request/url_fetcher.h"
 #include "url/gurl.h"
 
 namespace metrics {
 
 NetMetricsLogUploader::NetMetricsLogUploader(
     net::URLRequestContextGetter* request_context_getter,
-    const std::string& server_url,
-    const std::string& mime_type,
+    const base::StringPiece& server_url,
+    const base::StringPiece& mime_type,
     MetricsLogUploader::MetricServiceType service_type,
     const base::Callback<void(int)>& on_upload_complete)
-    : MetricsLogUploader(server_url,
-                         mime_type,
-                         service_type,
-                         on_upload_complete),
-      request_context_getter_(request_context_getter) {}
+    : request_context_getter_(request_context_getter),
+      server_url_(server_url),
+      mime_type_(mime_type.data(), mime_type.size()),
+      service_type_(service_type),
+      on_upload_complete_(on_upload_complete) {}
 
 NetMetricsLogUploader::~NetMetricsLogUploader() {
 }
 
 void NetMetricsLogUploader::UploadLog(const std::string& compressed_log_data,
                                       const std::string& log_hash) {
   current_fetch_ =
       net::URLFetcher::Create(GURL(server_url_), net::URLFetcher::POST, this);
 
   auto service = data_use_measurement::DataUseUserData::UMA;
@@ skipping 31 matching lines @@
   DCHECK_EQ(current_fetch_.get(), source);
 
   int response_code = source->GetResponseCode();
   if (response_code == net::URLFetcher::RESPONSE_CODE_INVALID)
     response_code = -1;
   current_fetch_.reset();
   on_upload_complete_.Run(response_code);
 }
 
 }  // namespace metrics