PageLoadMetrics renderer and browser implementation.

components/page_load_metrics/common/page_load_timing.h

+// Copyright 2015 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 COMPONENTS_PAGE_LOAD_METRICS_COMMON_PAGE_LOAD_TIMING_H_
+#define COMPONENTS_PAGE_LOAD_METRICS_COMMON_PAGE_LOAD_TIMING_H_
+
+#include "base/time/time.h"
+
+namespace blink {
+class WebPerformance;
+}
+
+namespace page_load_metrics {
+
+// PageLoadTiming contains timing metrics associated with a page load. Many of
+// the metrics here are based on the Navigation Timing spec:
+// http://www.w3.org/TR/navigation-timing/.

[Bryan McQuade, 2015/09/04 20:53:18]

let's add a short comment to note that all TimeDeltas are relative to
navigation_start.

[Charlie Harrison, 2015/09/08 23:05:15]

Done.

+struct PageLoadTiming {
+ public:
+  PageLoadTiming();
+  PageLoadTiming(const blink::WebPerformance&);
+  ~PageLoadTiming();
+
+  bool operator==(const PageLoadTiming& other) const;
+
+  bool IsEmpty() const;
+
+  // Time that the navigation for the associated page was initiated.
+  base::Time navigation_start;
+
+  // Time that the first byte of the response is received.
+  base::TimeDelta response_start;
+
+  // Time immediately before the DOMContentLoaded event is fired.
+  base::TimeDelta dom_content_loaded_event_start;
+
+  // Time immediately before the load event is fired.
+  base::TimeDelta load_event_start;
+
+  // Time when the first layout is completed.
+  base::TimeDelta first_layout;
+
+  // If you add additional members, also be sure to update operator== and

[Bryan McQuade, 2015/09/04 20:53:18]

should add mention to update IsEmpty as well

[Charlie Harrison, 2015/09/08 23:05:15]

Done.

+  // page_load_metrics_messages.h
+};
+
+}  // namespace page_load_metrics
+
+#endif  // COMPONENTS_PAGE_LOAD_METRICS_COMMON_PAGE_LOAD_TIMING_H_