Convert //ios from scoped_ptr to std::unique_ptr.

ios/chrome/browser/safe_browsing/safe_browsing_blocking_page.mm

Index: ios/chrome/browser/safe_browsing/safe_browsing_blocking_page.mm
diff --git a/ios/chrome/browser/safe_browsing/safe_browsing_blocking_page.mm b/ios/chrome/browser/safe_browsing/safe_browsing_blocking_page.mm
index de757dd3f98fe564f32d2733c2b6aa45a93c813d..f013b6556c5de151f056c6bfff4e6b15e9680758 100644
--- a/ios/chrome/browser/safe_browsing/safe_browsing_blocking_page.mm
+++ b/ios/chrome/browser/safe_browsing/safe_browsing_blocking_page.mm
@@ -13,6 +13,7 @@
 #include "base/i18n/rtl.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
+#include "base/memory/ptr_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
@@ -151,7 +152,7 @@ SafeBrowsingBlockingPage::SafeBrowsingBlockingPage(
   reporting_info.extra_suffix = GetExtraMetricsSuffix();
   reporting_info.rappor_prefix = GetRapporPrefix();
   reporting_info.rappor_report_type = rappor::SAFEBROWSING_RAPPOR_TYPE;
-  controller_->set_metrics_helper(make_scoped_ptr(
+  controller_->set_metrics_helper(base::WrapUnique(
       new IOSChromeMetricsHelper(web_state, request_url(), reporting_info)));
   controller_->metrics_helper()->RecordUserDecision(
       security_interstitials::MetricsHelper::SHOW);