SystemMonitor refactoring: move power state monitor into a separate class called PowerMonitor

base/power_monitor/power_monitor_android.cc

Index: base/power_monitor/power_monitor_android.cc
diff --git a/base/system_monitor/system_monitor_android.cc b/base/power_monitor/power_monitor_android.cc
similarity index 74%
rename from base/system_monitor/system_monitor_android.cc
rename to base/power_monitor/power_monitor_android.cc
index c86076d2a84baaaf1a20ec489ddbffdc46af7e7d..dbcb4d3bca04a2f688604be961e48896bb7312c2 100644
--- a/base/system_monitor/system_monitor_android.cc
+++ b/base/power_monitor/power_monitor_android.cc
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 namespace base {
 
-bool SystemMonitor::IsBatteryPower() {
+bool PowerMonitor::IsBatteryPower() {
   NOTIMPLEMENTED();
   return true;
 }