[page_load_metrics] User Initiated Abort Tracking (Observer version)

components/page_load_metrics/browser/page_load_metrics_util.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_BROWSER_PAGE_LOAD_METRICS_UTIL_H_
 #define COMPONENTS_PAGE_LOAD_METRICS_BROWSER_PAGE_LOAD_METRICS_UTIL_H_
 
 #include "base/metrics/histogram_macros.h"
 #include "base/time/time.h"
+#include "components/page_load_metrics/browser/page_load_metrics_observer.h"
 
 #define PAGE_LOAD_HISTOGRAM(name, sample)                           \
   UMA_HISTOGRAM_CUSTOM_TIMES(name, sample,                          \
                              base::TimeDelta::FromMilliseconds(10), \
                              base::TimeDelta::FromMinutes(10), 100)
 
 namespace page_load_metrics {
 
 struct PageLoadTiming;
 
 // Get the time of the first 'contentful' paint. A contentful paint is a paint
 // that includes content of some kind (for example, text or image content).
 // Painting of a background color is not considered 'contentful'.
 base::TimeDelta GetFirstContentfulPaint(const PageLoadTiming& timing);
 
+// Returns a TimeDelta which is infinity if we were never backgrounded. This is
+// a helper function to help with simpler metric comparisons.
+base::TimeDelta GetBackgroundDelta(const PageLoadExtraInfo& info);

[kinuko, 2015/12/09 04:57:51]

nit: I feel the method name and comment are a bit vague to be a public utility
method; what 'background delta'?  What 'simpler metric comparisons' means?

If we always compare the return value to a given timing value, could this method
be instead:

bool IsAfterBackgrounded(const TimeDelta& timing)

and could it do the comparison within the method?

[Charlie Harrison, 2015/12/09 22:46:43]

Good point. ricea is fixing this in his CL here
https://codereview.chromium.org/1507813002/
I'll merge with his change once that gets settled.

+
 }  // namespace page_load_metrics
 
 #endif  // COMPONENTS_PAGE_LOAD_METRICS_BROWSER_PAGE_LOAD_METRICS_UTIL_H_