media: Add UMA to record time to GenerateRequest and LoadSession

media/blink/cdm_result_promise_helper.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 "media/blink/cdm_result_promise_helper.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 
 namespace media {
@@ skipping 52 matching lines @@
     return;
 
   base::LinearHistogram::FactoryGet(
       uma_name,
       1,
       NUM_RESULT_CODES,
       NUM_RESULT_CODES + 1,
       base::HistogramBase::kUmaTargetedHistogramFlag)->Add(result);
 }
 
+void ReportTimeUMA(const std::string& uma_name, base::TimeDelta time) {
+  // Note: This leaks memory, which is expected behavior.
+  base::HistogramBase* histogram = base::Histogram::FactoryTimeGet(
+      uma_name, base::TimeDelta::FromMilliseconds(1),
+      base::TimeDelta::FromSeconds(10), 50,
+      base::HistogramBase::kUmaTargetedHistogramFlag);
+
+  histogram->AddTime(time);

[Ilya Sherman, 2017/02/11 00:50:53]

Please use "base::UmaHistogramTimes(name, time);" here.

[xhwang, 2017/02/11 01:12:45]

Great. Didn't know this existed. PTAL again!

+}
+
 }  // namespace media