Use StringPiece for CreateUploader/NetMetricsLogUploader params.

android_webview/native/aw_metrics_service_client_impl.cc

 // Copyright 2017 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 "android_webview/native/aw_metrics_service_client_impl.h"
 
 #include "android_webview/common/aw_version_info_values.h"
 #include "android_webview/jni/AwMetricsServiceClient_jni.h"
 #include "base/bind.h"
 #include "base/files/file_util.h"
@@ skipping 185 matching lines @@
   done_callback.Run();
 }
 
 void AwMetricsServiceClientImpl::CollectFinalMetricsForLog(
     const base::Closure& done_callback) {
   done_callback.Run();
 }
 
 std::unique_ptr<metrics::MetricsLogUploader>
 AwMetricsServiceClientImpl::CreateUploader(
-    const std::string& server_url,
-    const std::string& mime_type,
+    base::StringPiece server_url,
+    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 AwMetricsServiceClientImpl::GetStandardUploadInterval() {
   return base::TimeDelta::FromMinutes(kUploadIntervalMinutes);
@@ skipping 12 matching lines @@
     const base::android::JavaParamRef<jclass>& jcaller,
     jboolean enabled) {
   g_lazy_instance_.Pointer()->SetMetricsEnabled(enabled);
 }
 
 bool RegisterAwMetricsServiceClient(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android_webview