Implement LoadLog, and hook up HostResolverImpl to LoadLog....

net/base/load_log.cc

+// Copyright (c) 2009 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 "net/base/load_log.h"
+
+namespace net {
+
+LoadLog::LoadLog() {
+}
+
+// static
+const char* LoadLog::EventTypeToString(EventType event) {
+  switch (event) {
+#define EVENT_TYPE(label) case TYPE_ ## label: return #label;
+#include "net/base/load_log_event_type_list.h"
+#undef EVENT_TYPE
+  }
+  return NULL;
+}
+
+void LoadLog::Add(base::TimeTicks t, EventType event, EventPhase phase) {
+  // Minor optimization. TODO(eroman): use StackVector instead.
+  if (events_.empty())
+    events_.reserve(kMaxNumEntries / 2);
+
+  // Enforce a bound of kMaxNumEntries -- when we reach it, make it so the
+  // final entry in the list is |TYPE_LOG_TRUNCATED|.
+
+  if (events_.size() + 1 == kMaxNumEntries)
+    events_.push_back(Event(t, TYPE_LOG_TRUNCATED, PHASE_NONE));
+
+  if (events_.size() < kMaxNumEntries)
+    events_.push_back(Event(t, event, phase));
+}
+
+}  // namespace net