Convert //components/metrics from scoped_ptr to std::unique_ptr

components/metrics/metrics_log_manager.cc

Index: components/metrics/metrics_log_manager.cc
diff --git a/components/metrics/metrics_log_manager.cc b/components/metrics/metrics_log_manager.cc
index 661dacfa55fd20dc8b54ab20f3376a00da934e84..415db78565618177b2e820984ee222efdbcc1dd8 100644
--- a/components/metrics/metrics_log_manager.cc
+++ b/components/metrics/metrics_log_manager.cc
@@ -53,7 +53,7 @@ MetricsLogManager::MetricsLogManager(PrefService* local_state,
 
 MetricsLogManager::~MetricsLogManager() {}
 
-void MetricsLogManager::BeginLoggingWithLog(scoped_ptr<MetricsLog> log) {
+void MetricsLogManager::BeginLoggingWithLog(std::unique_ptr<MetricsLog> log) {
   DCHECK(!current_log_);
   current_log_ = std::move(log);
 }