Collect tab timing information for use in telementry-based startup tests

content/renderer/stats_collection_observer.cc

+// Copyright (c) 2013 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 "content/renderer/stats_collection_observer.h"
+
+#include "base/time.h"
+#include "content/renderer/render_view_impl.h"
+
+namespace content {
+
+StatsCollectionObserver::StatsCollectionObserver(RenderViewImpl* render_view)
+    : RenderViewObserver(render_view) {
+}
+
+StatsCollectionObserver::~StatsCollectionObserver() {
+}
+
+void StatsCollectionObserver::DidStartLoading() {
+  DCHECK(start_time_.is_null());
+  start_time_ = base::TimeTicks::Now();
+}
+
+void StatsCollectionObserver::DidStopLoading() {
+  DCHECK(stop_time_.is_null());
+  stop_time_ = base::TimeTicks::Now();
+
+  // Stop observing so we don't get called again.
+  RenderViewImpl* impl = static_cast<RenderViewImpl*>(render_view());
+  impl->RemoveObserver(this);
+}
+
+}  // namespace content