Merge subprocess metrics into global StatisticsRecorder.

components/metrics/metrics_service.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.
 
 //------------------------------------------------------------------------------
 // Description of the life cycle of a instance of MetricsService.
 //
 //  OVERVIEW
 //
 // A MetricsService instance is typically created at application startup.  It is
@@ skipping 1101 matching lines @@
 
 void MetricsService::RecordCurrentEnvironment(MetricsLog* log) {
   std::vector<variations::ActiveGroupId> synthetic_trials;
   GetSyntheticFieldTrialsOlderThan(log->creation_time(), &synthetic_trials);
   log->RecordEnvironment(metrics_providers_.get(), synthetic_trials,
                          GetInstallDate(), GetMetricsReportingEnabledDate());
 }
 
 void MetricsService::RecordCurrentHistograms() {
   DCHECK(log_manager_.current_log());
+
+  // Merge any data from metrics providers into the global StatisticsRecorder.
+  for (MetricsProvider* provider : metrics_providers_)
+    provider->MergeHistogramDeltas();
+
   histogram_snapshot_manager_.StartDeltas();
   // "true" to the begin() call indicates that StatisticsRecorder should include
   // histograms held in persistent storage.
   histogram_snapshot_manager_.PrepareDeltasWithoutStartFinish(
       base::StatisticsRecorder::begin(true), base::StatisticsRecorder::end(),
       base::Histogram::kNoFlags, base::Histogram::kUmaTargetedHistogramFlag);
   for (MetricsProvider* provider : metrics_providers_)
     provider->RecordHistogramSnapshots(&histogram_snapshot_manager_);
   histogram_snapshot_manager_.FinishDeltas();
 }
@@ skipping 40 matching lines @@
                  base::Time::Now().ToTimeT());
 }
 
 void MetricsService::SkipAndDiscardUpload() {
   log_manager_.DiscardStagedLog();
   scheduler_->UploadCancelled();
   log_upload_in_progress_ = false;
 }
 
 }  // namespace metrics