Initial UKMPageLoadMetricsObserver

components/ukm/ukm_service.cc

Index: components/ukm/ukm_service.cc
diff --git a/components/ukm/ukm_service.cc b/components/ukm/ukm_service.cc
index 285dedfa4bda02189f48e76e7c2690c575d5a099..7a4272e348a61125568b87bbc59341563d8b4c4a 100644
--- a/components/ukm/ukm_service.cc
+++ b/components/ukm/ukm_service.cc
@@ -15,11 +15,13 @@
 #include "components/metrics/metrics_log_uploader.h"
 #include "components/metrics/metrics_service_client.h"
 #include "components/metrics/proto/ukm/report.pb.h"
+#include "components/metrics/proto/ukm/source.pb.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
 #include "components/ukm/metrics_reporting_scheduler.h"
 #include "components/ukm/persisted_logs_metrics_impl.h"
 #include "components/ukm/ukm_pref_names.h"
+#include "components/ukm/ukm_source.h"
 #include "components/variations/variations_associated_data.h"
 
 namespace ukm {
@@ -59,6 +61,9 @@ const int kMinPersistedBytes = 300000;
 // limit is exceeded.
 const size_t kMaxLogRetransmitSize = 100 * 1024;
 
+// Maximum number of Sources we'll keep around before dropping new ones.
+const size_t kMaxSourcesLength = 100;
+
 std::string GetServerUrl() {
   std::string server_url = variations::GetVariationParamValue(
       kUkmRolloutFieldTrialName, kUkmRolloutServerUrlParam);
@@ -175,7 +180,13 @@ void UkmService::BuildAndStoreLog() {
   Report report;
   report.set_client_id(client_id_);
   // TODO(holte): Populate system_profile.
-  // TODO(zhenw): Populate sources.
+
+  for (auto& source : sources_) {
+    Source* proto_source = report.add_sources();
+    source->PopulateProto(proto_source);
+  }
+  sources_.clear();
+
   std::string serialized_log;
   report.SerializeToString(&serialized_log);
   persisted_logs_.StoreLog(serialized_log);
@@ -232,4 +243,11 @@ void UkmService::OnLogUploadComplete(int response_code) {
   scheduler_->UploadFinished(server_is_healthy, !persisted_logs_.empty());
 }
 
+void UkmService::RecordSource(std::unique_ptr<UkmSource> source) {
+  if (sources_.size() >= kMaxSourcesLength)
+    return;
+
+  sources_.push_back(std::move(source));
+}
+
 }  // namespace ukm