Histogram for recording actual log upload interval added.

components/metrics/metrics_reporting_scheduler.cc

 // Copyright 2014 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 "components/metrics/metrics_reporting_scheduler.h"
 
 #include "base/compiler_specific.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 44 matching lines @@
   TIMER_FIRED_FIRST,
   INIT_TASK_COMPLETED_FIRST,
   INIT_SEQUENCE_ENUM_SIZE,
 };
 
 void LogMetricsInitSequence(InitSequence sequence) {
   UMA_HISTOGRAM_ENUMERATION("UMA.InitSequence", sequence,
                             INIT_SEQUENCE_ENUM_SIZE);
 }
 
+void LogActualUploadInterval(TimeDelta interval) {
+   UMA_HISTOGRAM_CUSTOM_COUNTS("UMA.ActualLogUploadInterval",

[Alexei Svitkine (slow), 2014/10/15 21:14:45]

Nit: I think this is indented 1 space too much. Please fix.

+                               interval.InMinutes(),
+                               1,
+                               base::TimeDelta::FromHours(12).InMinutes(),
+                               50);
+}
+
 // Returns upload interval specified for the current experiment running.
 // TODO(gayane): Only for experimenting with upload interval for Android
 // (bug: 17391128). Should be removed once the experiments are done.
 base::TimeDelta GetUploadIntervalFromExperiment() {
   std::string interval_str = variations::GetVariationParamValue(
       "UMALogUploadInterval", "interval");
   int interval;
   if (interval_str.empty() || !base::StringToInt(interval_str, &interval))
     return TimeDelta::FromSeconds(kStandardUploadIntervalSeconds);
 
@@ skipping 44 matching lines @@
   callback_pending_ = false;
   // If the server is having issues, back off. Otherwise, reset to default
   // (unless there are more logs to send, in which case the next upload should
   // happen sooner).
   if (!server_is_healthy) {
     BackOffUploadInterval();
   } else if (more_logs_remaining) {
     upload_interval_ = TimeDelta::FromSeconds(kUnsentLogsIntervalSeconds);
   } else {
     upload_interval_ = GetStandardUploadInterval();
+    last_upload_finish_time_ = base::TimeTicks::Now();
   }
 
   if (running_)
     ScheduleNextUpload();
 }
 
 void MetricsReportingScheduler::UploadCancelled() {
   DCHECK(callback_pending_);
   callback_pending_ = false;
   if (running_)
     ScheduleNextUpload();
 }
 
 void MetricsReportingScheduler::SetUploadIntervalForTesting(
     base::TimeDelta interval) {
   upload_interval_ = interval;
 }
 
 void MetricsReportingScheduler::TriggerUpload() {
   // If the timer fired before the init task has completed, don't trigger the
   // upload yet - wait for the init task to complete and do it then.
   if (!init_task_complete_) {
     LogMetricsInitSequence(TIMER_FIRED_FIRST);
     waiting_for_init_task_complete_ = true;
     return;
   }
+
+  if (!last_upload_finish_time_.is_null()) {
+    LogActualUploadInterval(base::TimeTicks::Now() - last_upload_finish_time_);
+    last_upload_finish_time_= base::TimeTicks();

[Alexei Svitkine (slow), 2014/10/15 21:14:45]

Nit: Space =.

+  }
+
   callback_pending_ = true;
   upload_callback_.Run();
 }
 
 void MetricsReportingScheduler::ScheduleNextUpload() {
   DCHECK(running_);
   if (upload_timer_.IsRunning() || callback_pending_)
     return;
 
   upload_timer_.Start(FROM_HERE, upload_interval_, this,
@@ skipping 14 matching lines @@
 
 base::TimeDelta MetricsReportingScheduler::GetStandardUploadInterval() {
 #if defined(OS_ANDROID)
   return GetUploadIntervalFromExperiment();
 #else
   return TimeDelta::FromSeconds(kStandardUploadIntervalSeconds);
 #endif
 }
 
 }  // namespace metrics