Add UKM metric tracking for various page load metric observers.

chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.cc

Index: chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.cc
diff --git a/chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.cc b/chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.cc
index fc22351bc7ddf618a3f56383715edc89aaaacd39..f691068538674fca5ac63be071c34f14eadcfc7b 100644
--- a/chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.cc
+++ b/chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.cc
@@ -4,10 +4,13 @@
 
 #include "chrome/browser/page_load_metrics/observers/subresource_filter_metrics_observer.h"
 
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
 #include "components/subresource_filter/content/browser/content_subresource_filter_driver_factory.h"
 #include "components/subresource_filter/content/browser/subresource_filter_safe_browsing_activation_throttle.h"
 #include "components/subresource_filter/core/common/activation_decision.h"
+#include "components/ukm/public/ukm_entry_builder.h"
+#include "components/ukm/public/ukm_recorder.h"
 #include "third_party/WebKit/public/platform/WebLoadingBehaviorFlag.h"
 
 using subresource_filter::ContentSubresourceFilterDriverFactory;
@@ -113,6 +116,9 @@ const char kHistogramSubresourceFilterActivationDecision[] =
 const char kHistogramSubresourceFilterActivationDecisionReload[] =
     "PageLoad.Clients.SubresourceFilter.ActivationDecision.LoadType.Reload";
 
+const char kUkmSubresourceFilterName[] = "SubresourceFilter";
+const char kUkmSubresourceFilterActivationDecision[] = "ActivationDecision";
+
 }  // namespace internal
 
 namespace {
@@ -123,7 +129,6 @@ void LogActivationDecisionMetrics(content::NavigationHandle* navigation_handle,
       internal::kHistogramSubresourceFilterActivationDecision,
       static_cast<int>(decision),
       static_cast<int>(ActivationDecision::ACTIVATION_DECISION_MAX));
-
   if (SubresourceFilterSafeBrowsingActivationThrottle::NavigationIsPageReload(
           navigation_handle)) {
     UMA_HISTOGRAM_ENUMERATION(
@@ -185,6 +190,16 @@ SubresourceFilterMetricsObserver::OnCommit(
   DCHECK(scoped_observer_.IsObservingSources());
   LogActivationDecisionMetrics(navigation_handle, *activation_decision_);
   scoped_observer_.RemoveAll();
+
+  ukm::UkmRecorder* ukm_recorder = g_browser_process->ukm_recorder();
+  if (ukm_recorder) {
+    std::unique_ptr<ukm::UkmEntryBuilder> builder =
+        ukm_recorder->GetEntryBuilder(source_id,
+                                      internal::kUkmSubresourceFilterName);
+    builder->AddMetric(internal::kUkmSubresourceFilterActivationDecision,
+                       static_cast<int64_t>(*activation_decision_));
+  }
+
   return CONTINUE_OBSERVING;
 }