Battery Status API: add UMA logging for Android.

content/browser/battery_status/battery_status_manager_android.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 "content/browser/battery_status/battery_status_manager.h"
 
 #include "base/android/jni_android.h"
+#include "base/metrics/histogram.h"
 #include "jni/BatteryStatusManager_jni.h"
 
 using base::android::AttachCurrentThread;
 
 namespace content {
 
 BatteryStatusManager::BatteryStatusManager(
     const BatteryStatusService::BatteryUpdateCallback& callback)
     : callback_(callback) {
   j_manager_.Reset(
@@ skipping 16 matching lines @@
     jdouble level) {
   blink::WebBatteryStatus status;
   status.charging = charging;
   status.chargingTime = charging_time;
   status.dischargingTime = discharging_time;
   status.level = level;
   callback_.Run(status);
 }
 
 bool BatteryStatusManager::StartListeningBatteryChange() {
-  return Java_BatteryStatusManager_start(
-      AttachCurrentThread(), j_manager_.obj(),
-      reinterpret_cast<intptr_t>(this));
+  bool result = Java_BatteryStatusManager_start(AttachCurrentThread(),
+      j_manager_.obj(), reinterpret_cast<intptr_t>(this));
+  UMA_HISTOGRAM_BOOLEAN("BatteryStatus.StartAndroid", result);
+  return result;
 }
 
 void BatteryStatusManager::StopListeningBatteryChange() {
   Java_BatteryStatusManager_stop(
       AttachCurrentThread(), j_manager_.obj());
 }
 
 }  // namespace content