Adding TabRestore PLM UMA

chrome/browser/page_load_metrics/page_load_metrics_initialize.cc

Index: chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
diff --git a/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc b/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
index a409b5eacb73f1a16cd1eed0c86dd8459272f852..3af2ffdd7c944087f97252bee700dfd963bb1a8a 100644
--- a/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
+++ b/chrome/browser/page_load_metrics/page_load_metrics_initialize.cc
@@ -26,6 +26,7 @@
 #include "chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/service_worker_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.h"
+#include "chrome/browser/page_load_metrics/observers/tab_restore_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_embedder_interface.h"
 #include "chrome/browser/page_load_metrics/page_load_tracker.h"
@@ -88,6 +89,7 @@ void PageLoadMetricsEmbedder::RegisterObservers(
             web_contents_->GetBrowserContext()));
     tracker->AddObserver(base::MakeUnique<CssScanningMetricsObserver>());
     tracker->AddObserver(base::MakeUnique<ProtocolPageLoadMetricsObserver>());
+    tracker->AddObserver(base::MakeUnique<TabRestorePageLoadMetricsObserver>());
 
     std::unique_ptr<page_load_metrics::PageLoadMetricsObserver> ukm_observer =
         UkmPageLoadMetricsObserver::CreateIfNeeded();