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

content/renderer/stats_collection_observer.h

+// 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.
+
+#ifndef CONTENT_RENDERER_STATS_COLLECTION_OBSERVER_H_
+#define CONTENT_RENDERER_STATS_COLLECTION_OBSERVER_H_
+
+#include "base/time.h"
+#include "content/public/renderer/render_view_observer.h"
+
+namespace content {
+
+class RenderViewImpl;
+
+// Collect timing information for page loads.
+// If a Renderview performs multiple loads, only the first one is recorded.
+class StatsCollectionObserver : public RenderViewObserver {
+ public:
+  explicit StatsCollectionObserver(RenderViewImpl* render_view);
+  virtual ~StatsCollectionObserver();
+
+  // RenderViewObserver implementation
+  virtual void DidStartLoading() OVERRIDE;
+  virtual void DidStopLoading() OVERRIDE;
+
+  // Timing for the page load start and stop.  These functions may return
+  // a null time value under various circumstances.
+  const base::TimeTicks& load_start_time() { return start_time_; }
+  const base::TimeTicks& load_stop_time() { return stop_time_; }
+
+ private:
+  base::TimeTicks start_time_;
+  base::TimeTicks stop_time_;
+
+   DISALLOW_COPY_AND_ASSIGN(StatsCollectionObserver);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_STATS_COLLECTION_OBSERVER_H_