Basic UkmService implementation

components/metrics/persisted_logs.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/metrics/persisted_logs.h"
 
 #include <memory>
 #include <string>
 #include <utility>
 
@@ skipping 91 matching lines @@
   DCHECK(has_staged_log());
 }
 
 void PersistedLogs::DiscardStagedLog() {
   DCHECK(has_staged_log());
   DCHECK_LT(static_cast<size_t>(staged_log_index_), list_.size());
   list_.erase(list_.begin() + staged_log_index_);
   staged_log_index_ = -1;
 }
 
+void PersistedLogs::Purge() {
+  if (has_staged_log()) {
+    DiscardStagedLog();
+  }
+  list_.clear();
+  local_state_->ClearPref(pref_name_);
+}
+
 PersistedLogs::LogReadStatus PersistedLogs::ReadLogsFromPrefList(
     const base::ListValue& list_value) {
   if (list_value.empty())
     return metrics_->RecordLogReadStatus(LIST_EMPTY);
 
   const size_t log_count = list_value.GetSize();
 
   DCHECK(list_.empty());
   list_.resize(log_count);
 
@@ skipping 55 matching lines @@
     dict_value->SetString(kLogDataKey,
                           EncodeToBase64(list_[i].compressed_log_data));
     dict_value->SetString(kLogTimestampKey, list_[i].timestamp);
     list_value->Append(std::move(dict_value));
   }
   if (dropped_logs_num > 0)
     metrics_->RecordDroppedLogsNum(dropped_logs_num);
 }
 
 }  // namespace metrics