Allow PolicyLoadStatusSample to override reporting method

components/policy/core/common/policy_load_status.cc

 // Copyright (c) 2013 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/policy/core/common/policy_load_status.h"
 
+#include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/stringprintf.h"
 #include "components/policy/core/common/policy_types.h"
 
 namespace policy {
 
 namespace {
 
 const char kHistogramName[] = "Enterprise.PolicyLoadStatus";
 
+void ReportPolicyLoadStatus(base::HistogramBase* histogram,
+                            PolicyLoadStatus status) {
+  histogram->Add(status);
+}
+
 }  // namespace
 
-PolicyLoadStatusSample::PolicyLoadStatusSample()
-    : histogram_(base::LinearHistogram::FactoryGet(
-          kHistogramName, 1, POLICY_LOAD_STATUS_SIZE,
-          POLICY_LOAD_STATUS_SIZE + 1,
-          base::Histogram::kUmaTargetedHistogramFlag)) {
+PolicyLoadStatusSample::PolicyLoadStatusSample(
+    const ReportCallback& report_callback)
+    : report_callback_(report_callback) {
+  // Report to a base::LinearHistogram by default.
+  if (report_callback_.is_null()) {
+    base::HistogramBase* histogram(base::LinearHistogram::FactoryGet(
+        kHistogramName, 1, POLICY_LOAD_STATUS_SIZE, POLICY_LOAD_STATUS_SIZE + 1,
+        base::Histogram::kUmaTargetedHistogramFlag));
+    report_callback_ = base::Bind(&ReportPolicyLoadStatus, histogram);
+  }
+
   Add(POLICY_LOAD_STATUS_STARTED);
 }
 
 PolicyLoadStatusSample::~PolicyLoadStatusSample() {
   for (int i = 0; i < POLICY_LOAD_STATUS_SIZE; ++i) {
     if (status_bits_[i])
-      histogram_->Add(i);
+      report_callback_.Run(static_cast<PolicyLoadStatus>(i));
   }
 }
 
 void PolicyLoadStatusSample::Add(PolicyLoadStatus status) {
   status_bits_[status] = true;
 }
 
 }  // namespace policy