Use StringPiece for CreateUploader/NetMetricsLogUploader params.

chromecast/browser/metrics/cast_metrics_service_client.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 "chromecast/browser/metrics/cast_metrics_service_client.h"
 
 #include "base/command_line.h"
 #include "base/guid.h"
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
@@ skipping 225 matching lines @@
   if (command_line->HasSwitch(switches::kOverrideMetricsUploadUrl)) {
     uma_server_url.assign(
         command_line->GetSwitchValueASCII(switches::kOverrideMetricsUploadUrl));
   }
   DCHECK(!uma_server_url.empty());
   return uma_server_url;
 }
 
 std::unique_ptr<::metrics::MetricsLogUploader>
 CastMetricsServiceClient::CreateUploader(
-    const std::string& server_url,
-    const std::string& mime_type,
+    const base::StringPiece& server_url,
+    const base::StringPiece& mime_type,
     ::metrics::MetricsLogUploader::MetricServiceType service_type,
     const base::Callback<void(int)>& on_upload_complete) {
   return std::unique_ptr<::metrics::MetricsLogUploader>(
       new ::metrics::NetMetricsLogUploader(request_context_, server_url,
                                            mime_type, service_type,
                                            on_upload_complete));
 }
 
 base::TimeDelta CastMetricsServiceClient::GetStandardUploadInterval() {
   return base::TimeDelta::FromMinutes(kStandardUploadIntervalMinutes);
@@ skipping 146 matching lines @@
   external_metrics_->StopAndDestroy();
   external_metrics_ = nullptr;
   platform_metrics_->StopAndDestroy();
   platform_metrics_ = nullptr;
 #endif  // defined(OS_LINUX)
   metrics_service_->Stop();
 }
 
 }  // namespace metrics
 }  // namespace chromecast