Split the power monitoring feature from SystemMonitor

The SystemMonitor is a mixed monitor which not only monitors
the power state changes but also the devices changes. This
patch is to separate the power monitor from SystemMonitor
as a new class PowerMonitor which is dedicated to monitor
power state.

The next step is to seek a opportunity to refactor SystemMonitor
as something like DeviceMonitor.

BUG=149059
TEST=base_unittests --gtest_filter=PowerMonitorTest.*

Review URL: https://chromiumcodereview.appspot.com/10959020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192114 0039d316-1c4b-4281-b951-d872f2087c98

43 files changed, 576 insertions, 469 deletions

diff --git a/base/android/base_jni_registrar.cc b/base/android/base_jni_registrar.cc
index 6aabd0d..105d03f 100644
--- a/base/android/base_jni_registrar.cc
+++ b/base/android/base_jni_registrar.cc
@@ -15,7 +15,7 @@
 #include "base/android/path_utils.h"
 #include "base/android/thread_utils.h"
 #include "base/message_pump_android.h"
-#include "base/system_monitor/system_monitor_android.h"
+#include "base/power_monitor/power_monitor_android.h"
 
 namespace base {
 namespace android {
@@ -29,7 +29,7 @@ static RegistrationMethod kBaseRegisteredMethods[] = {
   { "PathService", base::android::RegisterPathService },
   { "PathUtils", base::android::RegisterPathUtils },
   { "SystemMessageHandler", base::MessagePumpForUI::RegisterBindings },
-  { "SystemMonitor", base::RegisterSystemMonitor },
+  { "PowerMonitor", base::RegisterPowerMonitor },
   { "ThreadUtils", base::RegisterThreadUtils },
 };
 
diff --git a/base/android/java/src/org/chromium/base/SystemMonitor.java b/base/android/java/src/org/chromium/base/PowerMonitor.java
index 138ae28..b7a691e 100644
--- a/base/android/java/src/org/chromium/base/SystemMonitor.java
+++ b/base/android/java/src/org/chromium/base/PowerMonitor.java
@@ -13,12 +13,15 @@ import android.os.Looper;
 
 
 /**
- * Integrates native SystemMonitor with the java side.
+ * Integrates native PowerMonitor with the java side.
  */
 @JNINamespace("base::android")
-public class SystemMonitor implements ActivityStatus.StateListener {
+public class PowerMonitor implements ActivityStatus.StateListener {
     private static final long SUSPEND_DELAY_MS = 1 * 60 * 1000;  // 1 minute.
-    private static SystemMonitor sInstance;
+    private static class LazyHolder {
+      private static final PowerMonitor INSTANCE = new PowerMonitor();
+    }
+    private static PowerMonitor sInstance;
 
     private boolean mIsBatteryPower;
     private final Handler mHandler = new Handler(Looper.getMainLooper());
@@ -38,12 +41,12 @@ public class SystemMonitor implements ActivityStatus.StateListener {
         // Applications will create this once the JNI side has been fully wired up both sides. For
         // tests, we just need native -> java, that is, we don't need to notify java -> native on
         // creation.
-        sInstance = new SystemMonitor();
+        sInstance = LazyHolder.INSTANCE;
     }
 
     public static void create(Context context) {
         if (sInstance == null) {
-            sInstance = new SystemMonitor();
+            sInstance = LazyHolder.INSTANCE;
             ActivityStatus.registerStateListener(sInstance);
             IntentFilter ifilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
             Intent batteryStatusIntent = context.registerReceiver(null, ifilter);
@@ -51,7 +54,7 @@ public class SystemMonitor implements ActivityStatus.StateListener {
         }
     }
 
-    private SystemMonitor() {
+    private PowerMonitor() {
     }
 
     public static void onBatteryChargingChanged(Intent intent) {
diff --git a/base/android/java/src/org/chromium/base/PowerStatusReceiver.java b/base/android/java/src/org/chromium/base/PowerStatusReceiver.java
index 89594b8..f36c146 100644
--- a/base/android/java/src/org/chromium/base/PowerStatusReceiver.java
+++ b/base/android/java/src/org/chromium/base/PowerStatusReceiver.java
@@ -11,13 +11,13 @@ import android.content.Intent;
 
 /**
  * A BroadcastReceiver that listens to changes in power status and notifies
- * SystemMonitor.
+ * PowerMonitor.
  * It's instantiated by the framework via the application intent-filter
  * declared in its manifest.
  */
 public class PowerStatusReceiver extends BroadcastReceiver {
     @Override
     public void onReceive(Context context, Intent intent) {
-        SystemMonitor.onBatteryChargingChanged(intent);
+        PowerMonitor.onBatteryChargingChanged(intent);
     }
 }
diff --git a/base/base.gyp b/base/base.gyp
index ea04cae..a8f2832 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -535,6 +535,7 @@
         'platform_file_unittest.cc',
         'posix/file_descriptor_shuffle_unittest.cc',
         'posix/unix_domain_socket_linux_unittest.cc',
+        'power_monitor/power_monitor_unittest.cc',
         'pr_time_unittest.cc',
         'prefs/default_pref_store_unittest.cc',
         'prefs/json_pref_store_unittest.cc',
@@ -1119,8 +1120,8 @@
             'android/java/src/org/chromium/base/LocaleUtils.java',
             'android/java/src/org/chromium/base/PathService.java',
             'android/java/src/org/chromium/base/PathUtils.java',
+            'android/java/src/org/chromium/base/PowerMonitor.java',
             'android/java/src/org/chromium/base/SystemMessageHandler.java',
-            'android/java/src/org/chromium/base/SystemMonitor.java',
             'android/java/src/org/chromium/base/ThreadUtils.java',
           ],
           'variables': {
diff --git a/base/base.gypi b/base/base.gypi
index 325dc6c..9f1dc84 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -345,6 +345,15 @@
           'posix/global_descriptors.h',
           'posix/unix_domain_socket_linux.cc',
           'posix/unix_domain_socket_linux.h',
+          'power_monitor/power_monitor.cc',
+          'power_monitor/power_monitor.h',
+          'power_monitor/power_monitor_android.cc',
+          'power_monitor/power_monitor_android.h',
+          'power_monitor/power_monitor_ios.mm',
+          'power_monitor/power_monitor_mac.mm',
+          'power_monitor/power_monitor_posix.cc',
+          'power_monitor/power_monitor_win.cc',
+          'power_monitor/power_observer.h',
           'process.h',
           'process_info.h',
           'process_info_mac.cc',
@@ -435,12 +444,6 @@
           'synchronization/waitable_event_win.cc',
           'system_monitor/system_monitor.cc',
           'system_monitor/system_monitor.h',
-          'system_monitor/system_monitor_android.cc',
-          'system_monitor/system_monitor_android.h',
-          'system_monitor/system_monitor_ios.mm',
-          'system_monitor/system_monitor_mac.mm',
-          'system_monitor/system_monitor_posix.cc',
-          'system_monitor/system_monitor_win.cc',
           'sys_byteorder.h',
           'sys_info.cc',
           'sys_info.h',
@@ -648,7 +651,7 @@
               'base_paths_posix.cc',
               'files/file_path_watcher_kqueue.cc',
               'files/file_path_watcher_stub.cc',
-              'system_monitor/system_monitor_posix.cc',
+              'power_monitor/power_monitor_posix.cc',
             ],
             'sources/': [
               ['include', '^files/file_path_watcher_linux\\.cc$'],
diff --git a/base/hi_res_timer_manager.h b/base/hi_res_timer_manager.h
index 1bd5538..763aede 100644
--- a/base/hi_res_timer_manager.h
+++ b/base/hi_res_timer_manager.h
@@ -6,17 +6,17 @@
 #define BASE_HI_RES_TIMER_MANAGER_H_
 
 #include "base/base_export.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/basictypes.h"
+#include "base/power_monitor/power_observer.h"
 
 // Ensures that the Windows high resolution timer is only used
 // when not running on battery power.
-class BASE_EXPORT HighResolutionTimerManager
-    : public base::SystemMonitor::PowerObserver {
+class BASE_EXPORT HighResolutionTimerManager : public base::PowerObserver {
  public:
   HighResolutionTimerManager();
   virtual ~HighResolutionTimerManager();
 
-  // base::SystemMonitor::PowerObserver:
+  // base::PowerObserver method.
   virtual void OnPowerStateChange(bool on_battery_power) OVERRIDE;
 
   // Returns true if the hi resolution clock could be used right now.
diff --git a/base/hi_res_timer_manager_unittest.cc b/base/hi_res_timer_manager_unittest.cc
index 07651ce..601586d 100644
--- a/base/hi_res_timer_manager_unittest.cc
+++ b/base/hi_res_timer_manager_unittest.cc
@@ -5,7 +5,8 @@
 #include "base/hi_res_timer_manager.h"
 
 #include "base/memory/scoped_ptr.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/message_loop.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -13,12 +14,12 @@
 // http://crbug.com/114048
 TEST(HiResTimerManagerTest, DISABLED_ToggleOnOff) {
   MessageLoop loop;
-  scoped_ptr<base::SystemMonitor> system_monitor(new base::SystemMonitor());
+  scoped_ptr<base::PowerMonitor> power_monitor(new base::PowerMonitor());
   HighResolutionTimerManager manager;
 
   // At this point, we don't know if the high resolution timers are on or off,
   // it depends on what system the tests are running on (for example, if this
-  // test is running on a laptop/battery, then the SystemMonitor would have
+  // test is running on a laptop/battery, then the PowerMonitor would have
   // already set the PowerState to battery power; but if we're running on a
   // desktop, then the PowerState will be non-battery power).  Simulate a power
   // level change to get to a deterministic state.
diff --git a/base/hi_res_timer_manager_win.cc b/base/hi_res_timer_manager_win.cc
index 1a92394..2a297dc 100644
--- a/base/hi_res_timer_manager_win.cc
+++ b/base/hi_res_timer_manager_win.cc
@@ -4,17 +4,18 @@
 
 #include "base/hi_res_timer_manager.h"
 
+#include "base/power_monitor/power_monitor.h"
 #include "base/time.h"
 
 HighResolutionTimerManager::HighResolutionTimerManager()
     : hi_res_clock_available_(false) {
-  base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
-  system_monitor->AddPowerObserver(this);
-  UseHiResClock(!system_monitor->BatteryPower());
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  power_monitor->AddObserver(this);
+  UseHiResClock(!power_monitor->BatteryPower());
 }
 
 HighResolutionTimerManager::~HighResolutionTimerManager() {
-  base::SystemMonitor::Get()->RemovePowerObserver(this);
+  base::PowerMonitor::Get()->RemoveObserver(this);
   UseHiResClock(false);
 }
 
diff --git a/base/power_monitor/power_monitor.cc b/base/power_monitor/power_monitor.cc
new file mode 100644
index 0000000..13e91c7
--- /dev/null
+++ b/base/power_monitor/power_monitor.cc
@@ -0,0 +1,106 @@
+// Copyright 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 "base/power_monitor/power_monitor.h"
+
+#include "base/time.h"
+
+namespace base {
+
+static PowerMonitor* g_power_monitor = NULL;
+
+#if defined(ENABLE_BATTERY_MONITORING)
+// The amount of time (in ms) to wait before running the initial
+// battery check.
+static int kDelayedBatteryCheckMs = 10 * 1000;
+#endif  // defined(ENABLE_BATTERY_MONITORING)
+
+PowerMonitor::PowerMonitor()
+    : observers_(new ObserverListThreadSafe<PowerObserver>()),
+      battery_in_use_(false),
+      suspended_(false) {
+  DCHECK(!g_power_monitor);
+  g_power_monitor = this;
+
+  DCHECK(MessageLoop::current());
+#if defined(ENABLE_BATTERY_MONITORING)
+  delayed_battery_check_.Start(FROM_HERE,
+      base::TimeDelta::FromMilliseconds(kDelayedBatteryCheckMs), this,
+      &PowerMonitor::BatteryCheck);
+#endif  // defined(ENABLE_BATTERY_MONITORING)
+#if defined(OS_MACOSX)
+  PlatformInit();
+#endif
+}
+
+PowerMonitor::~PowerMonitor() {
+#if defined(OS_MACOSX)
+  PlatformDestroy();
+#endif
+  DCHECK_EQ(this, g_power_monitor);
+  g_power_monitor = NULL;
+}
+
+// static
+PowerMonitor* PowerMonitor::Get() {
+  return g_power_monitor;
+}
+
+void PowerMonitor::AddObserver(PowerObserver* obs) {
+  observers_->AddObserver(obs);
+}
+
+void PowerMonitor::RemoveObserver(PowerObserver* obs) {
+  observers_->RemoveObserver(obs);
+}
+
+void PowerMonitor::ProcessPowerEvent(PowerEvent event_id) {
+  // Suppress duplicate notifications.  Some platforms may
+  // send multiple notifications of the same event.
+  switch (event_id) {
+    case POWER_STATE_EVENT:
+      {
+        bool on_battery = IsBatteryPower();
+        if (on_battery != battery_in_use_) {
+          battery_in_use_ = on_battery;
+          NotifyPowerStateChange();
+        }
+      }
+      break;
+    case RESUME_EVENT:
+      if (suspended_) {
+        suspended_ = false;
+        NotifyResume();
+      }
+      break;
+    case SUSPEND_EVENT:
+      if (!suspended_) {
+        suspended_ = true;
+        NotifySuspend();
+      }
+      break;
+  }
+}
+
+void PowerMonitor::BatteryCheck() {
+  ProcessPowerEvent(PowerMonitor::POWER_STATE_EVENT);
+}
+
+void PowerMonitor::NotifyPowerStateChange() {
+  DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
+           << " battery";
+  observers_->Notify(&PowerObserver::OnPowerStateChange, BatteryPower());
+}
+
+void PowerMonitor::NotifySuspend() {
+  DVLOG(1) << "Power Suspending";
+  observers_->Notify(&PowerObserver::OnSuspend);
+}
+
+void PowerMonitor::NotifyResume() {
+  DVLOG(1) << "Power Resuming";
+  observers_->Notify(&PowerObserver::OnResume);
+}
+
+}  // namespace base
diff --git a/base/power_monitor/power_monitor.h b/base/power_monitor/power_monitor.h
new file mode 100644
index 0000000..e893547
--- /dev/null
+++ b/base/power_monitor/power_monitor.h
@@ -0,0 +1,146 @@
+// Copyright 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.
+
+#ifndef BASE_POWER_MONITOR_POWER_MONITOR_H_
+#define BASE_POWER_MONITOR_POWER_MONITOR_H_
+
+#include "base/base_export.h"
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "base/observer_list_threadsafe.h"
+#include "base/power_monitor/power_observer.h"
+
+#if defined(OS_WIN)
+#include <windows.h>
+
+// Windows HiRes timers drain the battery faster so we need to know the battery
+// status.  This isn't true for other platforms.
+#define ENABLE_BATTERY_MONITORING 1
+#else
+#undef ENABLE_BATTERY_MONITORING
+#endif  // !OS_WIN
+
+#if defined(ENABLE_BATTERY_MONITORING)
+#include "base/timer.h"
+#endif  // defined(ENABLE_BATTERY_MONITORING)
+
+#if defined(OS_IOS)
+#include <objc/runtime.h>
+#endif  // OS_IOS
+
+namespace base {
+
+// A class used to monitor the power state change and notify the observers about
+// the change event.
+class BASE_EXPORT PowerMonitor {
+ public:
+  // Normalized list of power events.
+  enum PowerEvent {
+    POWER_STATE_EVENT,  // The Power status of the system has changed.
+    SUSPEND_EVENT,      // The system is being suspended.
+    RESUME_EVENT        // The system is being resumed.
+  };
+
+  PowerMonitor();
+  ~PowerMonitor();
+
+  // Get the application-wide PowerMonitor (if not present, returns NULL).
+  static PowerMonitor* Get();
+
+#if defined(OS_MACOSX)
+  // Allocate system resources needed by the PowerMonitor class.
+  //
+  // This function must be called before instantiating an instance of the class
+  // and before the Sandbox is initialized.
+#if !defined(OS_IOS)
+  static void AllocateSystemIOPorts();
+#else
+  static void AllocateSystemIOPorts() {}
+#endif  // OS_IOS
+#endif  // OS_MACOSX
+
+  // Add and remove an observer.
+  // Can be called from any thread.
+  // Must not be called from within a notification callback.
+  void AddObserver(PowerObserver* observer);
+  void RemoveObserver(PowerObserver* observer);
+
+  // Is the computer currently on battery power. Can be called on any thread.
+  bool BatteryPower() const {
+    // Using a lock here is not necessary for just a bool.
+    return battery_in_use_;
+  }
+
+ private:
+  friend class PowerMonitorTest;
+  // A friend function that is allowed to access the private ProcessPowerEvent.
+  friend void ProcessPowerEventHelper(PowerEvent);
+
+#if defined(OS_WIN)
+  // Represents a message-only window for power message handling on Windows.
+  // Only allow PowerMonitor to create it.
+  class PowerMessageWindow {
+   public:
+    PowerMessageWindow();
+    ~PowerMessageWindow();
+
+   private:
+    void ProcessWmPowerBroadcastMessage(int event_id);
+    LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
+                             WPARAM wparam, LPARAM lparam);
+    static LRESULT CALLBACK WndProcThunk(HWND hwnd,
+                                         UINT message,
+                                         WPARAM wparam,
+                                         LPARAM lparam);
+    // Instance of the module containing the window procedure.
+    HMODULE instance_;
+    // A hidden message-only window.
+    HWND message_hwnd_;
+  };
+#endif  // OS_WIN
+
+#if defined(OS_MACOSX)
+  void PlatformInit();
+  void PlatformDestroy();
+#endif
+
+  // Cross-platform handling of a power event.
+  void ProcessPowerEvent(PowerEvent event_id);
+
+  // Platform-specific method to check whether the system is currently
+  // running on battery power.  Returns true if running on batteries,
+  // false otherwise.
+  bool IsBatteryPower();
+
+  // Checks the battery status and notifies observers if the battery
+  // status has changed.
+  void BatteryCheck();
+
+  void NotifyPowerStateChange();
+  void NotifySuspend();
+  void NotifyResume();
+
+#if defined(OS_IOS)
+  // Holds pointers to system event notification observers.
+  std::vector<id> notification_observers_;
+#endif
+
+#if defined(ENABLE_BATTERY_MONITORING)
+  base::OneShotTimer<PowerMonitor> delayed_battery_check_;
+#endif
+
+  scoped_refptr<ObserverListThreadSafe<PowerObserver> > observers_;
+  bool battery_in_use_;
+  bool suspended_;
+
+#if defined(OS_WIN)
+  PowerMessageWindow power_message_window_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(PowerMonitor);
+};
+
+}  // namespace base
+
+#endif  // BASE_POWER_MONITOR_POWER_MONITOR_H_
diff --git a/base/power_monitor/power_monitor_android.cc b/base/power_monitor/power_monitor_android.cc
new file mode 100644
index 0000000..4900f6c
--- /dev/null
+++ b/base/power_monitor/power_monitor_android.cc
@@ -0,0 +1,42 @@
+// Copyright 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 "base/power_monitor/power_monitor.h"
+#include "jni/PowerMonitor_jni.h"
+
+namespace base {
+
+// A helper function which is a friend of PowerMonitor.
+void ProcessPowerEventHelper(PowerMonitor::PowerEvent event) {
+  if (base::PowerMonitor::Get())
+    base::PowerMonitor::Get()->ProcessPowerEvent(event);
+}
+
+namespace android {
+
+// Native implementation of PowerMonitor.java.
+void OnBatteryChargingChanged(JNIEnv* env, jclass clazz) {
+  ProcessPowerEventHelper(PowerMonitor::POWER_STATE_EVENT);
+}
+
+void OnMainActivityResumed(JNIEnv* env, jclass clazz) {
+  ProcessPowerEventHelper(PowerMonitor::RESUME_EVENT);
+}
+
+void OnMainActivitySuspended(JNIEnv* env, jclass clazz) {
+  ProcessPowerEventHelper(PowerMonitor::SUSPEND_EVENT);
+}
+
+}  // namespace android
+
+bool PowerMonitor::IsBatteryPower() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  return base::android::Java_PowerMonitor_isBatteryPower(env);
+}
+
+bool RegisterPowerMonitor(JNIEnv* env) {
+  return base::android::RegisterNativesImpl(env);
+}
+
+}  // namespace base
diff --git a/base/power_monitor/power_monitor_android.h b/base/power_monitor/power_monitor_android.h
new file mode 100644
index 0000000..7f43164
--- /dev/null
+++ b/base/power_monitor/power_monitor_android.h
@@ -0,0 +1,17 @@
+// Copyright 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.
+
+#ifndef BASE_POWER_MONITOR_POWER_MONITOR_ANDROID_H_
+#define BASE_POWER_MONITOR_POWER_MONITOR_ANDROID_H_
+
+#include <jni.h>
+
+namespace base {
+
+// Registers the JNI bindings for PowerMonitor.
+bool RegisterPowerMonitor(JNIEnv* env);
+
+}  // namespace base
+
+#endif  // BASE_POWER_MONITOR_POWER_MONITOR_ANDROID_H_
diff --git a/base/system_monitor/system_monitor_ios.mm b/base/power_monitor/power_monitor_ios.mm
index f3251b6..f7c0b92 100644
--- a/base/system_monitor/system_monitor_ios.mm
+++ b/base/power_monitor/power_monitor_ios.mm
@@ -1,34 +1,34 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 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 "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 #import <UIKit/UIKit.h>
 
 namespace base {
 
-void SystemMonitor::PlatformInit() {
+void PowerMonitor::PlatformInit() {
   NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
   id foreground =
       [nc addObserverForName:UIApplicationWillEnterForegroundNotification
                       object:nil
                        queue:nil
                   usingBlock:^(NSNotification* notification) {
-                      ProcessPowerMessage(RESUME_EVENT);
+                      ProcessPowerEvent(RESUME_EVENT);
                   }];
   id background =
       [nc addObserverForName:UIApplicationDidEnterBackgroundNotification
                       object:nil
                        queue:nil
                   usingBlock:^(NSNotification* notification) {
-                      ProcessPowerMessage(SUSPEND_EVENT);
+                      ProcessPowerEvent(SUSPEND_EVENT);
                   }];
   notification_observers_.push_back(foreground);
   notification_observers_.push_back(background);
 }
 
-void SystemMonitor::PlatformDestroy() {
+void PowerMonitor::PlatformDestroy() {
   NSNotificationCenter* nc = [NSNotificationCenter defaultCenter];
   for (std::vector<id>::iterator it = notification_observers_.begin();
        it != notification_observers_.end(); ++it) {
diff --git a/base/system_monitor/system_monitor_mac.mm b/base/power_monitor/power_monitor_mac.mm
index d0dbaab..ee906f6 100644
--- a/base/system_monitor/system_monitor_mac.mm
+++ b/base/power_monitor/power_monitor_mac.mm
@@ -1,17 +1,23 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 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.
 
 // Implementation based on sample code from
 // http://developer.apple.com/library/mac/#qa/qa1340/_index.html.
 
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 #include <IOKit/pwr_mgt/IOPMLib.h>
 #include <IOKit/IOMessage.h>
 
 namespace base {
 
+void ProcessPowerEventHelper(PowerMonitor::PowerEvent event) {
+  DCHECK(PowerMonitor::Get());
+  if (PowerMonitor::Get())
+    PowerMonitor::Get()->ProcessPowerEvent(event);
+}
+
 namespace {
 
 io_connect_t g_system_power_io_port = 0;
@@ -22,17 +28,15 @@ void SystemPowerEventCallback(void*,
                               io_service_t service,
                               natural_t message_type,
                               void* message_argument) {
-  SystemMonitor* sys_monitor = SystemMonitor::Get();
-  DCHECK(sys_monitor);
   switch (message_type) {
     case kIOMessageSystemWillSleep:
-      sys_monitor->ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
+      ProcessPowerEventHelper(base::PowerMonitor::SUSPEND_EVENT);
       IOAllowPowerChange(g_system_power_io_port,
           reinterpret_cast<intptr_t>(message_argument));
       break;
 
     case kIOMessageSystemWillPowerOn:
-      sys_monitor->ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
+      ProcessPowerEventHelper(PowerMonitor::RESUME_EVENT);
       break;
   }
 }
@@ -45,11 +49,10 @@ void SystemPowerEventCallback(void*,
 // See crbug.com/83783 .
 
 // static
-void SystemMonitor::AllocateSystemIOPorts() {
+void PowerMonitor::AllocateSystemIOPorts() {
   DCHECK_EQ(g_system_power_io_port, 0u);
 
   // Notification port allocated by IORegisterForSystemPower.
-
   g_system_power_io_port = IORegisterForSystemPower(
       NULL, &g_notification_port_ref, SystemPowerEventCallback,
       &g_notifier_object);
@@ -57,8 +60,8 @@ void SystemMonitor::AllocateSystemIOPorts() {
   DCHECK_NE(g_system_power_io_port, 0u);
 }
 
-void SystemMonitor::PlatformInit() {
-  // Need to call AllocateSystemIOPorts() before constructing a SystemMonitor
+void PowerMonitor::PlatformInit() {
+  // Need to call AllocateSystemIOPorts() before creating a PowerMonitor
   // object.
   DCHECK_NE(g_system_power_io_port, 0u);
   if (g_system_power_io_port == 0)
@@ -71,7 +74,7 @@ void SystemMonitor::PlatformInit() {
       kCFRunLoopCommonModes);
 }
 
-void SystemMonitor::PlatformDestroy() {
+void PowerMonitor::PlatformDestroy() {
   DCHECK_NE(g_system_power_io_port, 0u);
   if (g_system_power_io_port == 0)
     return;
diff --git a/base/system_monitor/system_monitor_posix.cc b/base/power_monitor/power_monitor_posix.cc
index 6cf01bf..affebea 100644
--- a/base/system_monitor/system_monitor_posix.cc
+++ b/base/power_monitor/power_monitor_posix.cc
@@ -1,12 +1,12 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright 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 "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 namespace base {
 
-bool SystemMonitor::IsBatteryPower() {
+bool PowerMonitor::IsBatteryPower() {
   NOTIMPLEMENTED();
   return false;
 }
diff --git a/base/power_monitor/power_monitor_unittest.cc b/base/power_monitor/power_monitor_unittest.cc
new file mode 100644
index 0000000..af3ed41
--- /dev/null
+++ b/base/power_monitor/power_monitor_unittest.cc
@@ -0,0 +1,106 @@
+// Copyright 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 "base/power_monitor/power_monitor.h"
+
+#include "base/message_loop.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+class PowerTest : public PowerObserver {
+ public:
+  PowerTest()
+      : power_state_changes_(0),
+        suspends_(0),
+        resumes_(0) {
+  }
+
+  // PowerObserver callbacks.
+  virtual void OnPowerStateChange(bool on_battery_power) OVERRIDE {
+    power_state_changes_++;
+  }
+
+  virtual void OnSuspend() OVERRIDE {
+    suspends_++;
+  }
+
+  virtual void OnResume() OVERRIDE {
+    resumes_++;
+  }
+
+  // Test status counts.
+  int power_state_changes() { return power_state_changes_; }
+  int suspends() { return suspends_; }
+  int resumes() { return resumes_; }
+
+ private:
+  int power_state_changes_;  // Count of OnPowerStateChange notifications.
+  int suspends_;  // Count of OnSuspend notifications.
+  int resumes_;  // Count of OnResume notifications.
+};
+
+class PowerMonitorTest : public testing::Test {
+ protected:
+  PowerMonitorTest() {
+#if defined(OS_MACOSX)
+    // This needs to happen before PowerMonitor's ctor.
+    PowerMonitor::AllocateSystemIOPorts();
+#endif
+    power_monitor_.reset(new PowerMonitor);
+  }
+
+  void ProcessPowerEvent(PowerMonitor::PowerEvent event_id) {
+    power_monitor_->ProcessPowerEvent(event_id);
+  }
+
+  virtual ~PowerMonitorTest() {}
+
+  MessageLoop message_loop_;
+  scoped_ptr<PowerMonitor> power_monitor_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerMonitorTest);
+};
+
+TEST_F(PowerMonitorTest, PowerNotifications) {
+  const int kObservers = 5;
+
+  PowerTest test[kObservers];
+  for (int index = 0; index < kObservers; ++index)
+    power_monitor_->AddObserver(&test[index]);
+
+  // Send a bunch of power changes.  Since the battery power hasn't
+  // actually changed, we shouldn't get notifications.
+  for (int index = 0; index < 5; index++) {
+    ProcessPowerEvent(PowerMonitor::POWER_STATE_EVENT);
+    EXPECT_EQ(test[0].power_state_changes(), 0);
+  }
+
+  // Sending resume when not suspended should have no effect.
+  ProcessPowerEvent(PowerMonitor::RESUME_EVENT);
+  message_loop_.RunUntilIdle();
+  EXPECT_EQ(test[0].resumes(), 0);
+
+  // Pretend we suspended.
+  ProcessPowerEvent(PowerMonitor::SUSPEND_EVENT);
+  message_loop_.RunUntilIdle();
+  EXPECT_EQ(test[0].suspends(), 1);
+
+  // Send a second suspend notification.  This should be suppressed.
+  ProcessPowerEvent(PowerMonitor::SUSPEND_EVENT);
+  message_loop_.RunUntilIdle();
+  EXPECT_EQ(test[0].suspends(), 1);
+
+  // Pretend we were awakened.
+  ProcessPowerEvent(PowerMonitor::RESUME_EVENT);
+  message_loop_.RunUntilIdle();
+  EXPECT_EQ(test[0].resumes(), 1);
+
+  // Send a duplicate resume notification.  This should be suppressed.
+  ProcessPowerEvent(PowerMonitor::RESUME_EVENT);
+  message_loop_.RunUntilIdle();
+  EXPECT_EQ(test[0].resumes(), 1);
+}
+
+}  // namespace base
diff --git a/base/system_monitor/system_monitor_win.cc b/base/power_monitor/power_monitor_win.cc
index 562b69b..67a6ce1 100644
--- a/base/system_monitor/system_monitor_win.cc
+++ b/base/power_monitor/power_monitor_win.cc
@@ -1,8 +1,8 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright 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 "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 
 #include "base/win/wrapped_window_proc.h"
 
@@ -16,7 +16,7 @@ const wchar_t kWindowClassName[] = L"Base_PowerMessageWindow";
 
 // Function to query the system to see if it is currently running on
 // battery power.  Returns true if running on battery.
-bool SystemMonitor::IsBatteryPower() {
+bool PowerMonitor::IsBatteryPower() {
   SYSTEM_POWER_STATUS status;
   if (!GetSystemPowerStatus(&status)) {
     DLOG_GETLASTERROR(ERROR) << "GetSystemPowerStatus failed";
@@ -25,13 +25,13 @@ bool SystemMonitor::IsBatteryPower() {
   return (status.ACLineStatus == 0);
 }
 
-SystemMonitor::PowerMessageWindow::PowerMessageWindow()
+PowerMonitor::PowerMessageWindow::PowerMessageWindow()
     : instance_(NULL), message_hwnd_(NULL) {
   WNDCLASSEX window_class;
   base::win::InitializeWindowClass(
       kWindowClassName,
       &base::win::WrappedWindowProc<
-          SystemMonitor::PowerMessageWindow::WndProcThunk>,
+          PowerMonitor::PowerMessageWindow::WndProcThunk>,
       0, 0, 0, NULL, NULL, NULL, NULL, NULL,
       &window_class);
   instance_ = window_class.hInstance;
@@ -44,29 +44,29 @@ SystemMonitor::PowerMessageWindow::PowerMessageWindow()
                    reinterpret_cast<LONG_PTR>(this));
 }
 
-SystemMonitor::PowerMessageWindow::~PowerMessageWindow() {
+PowerMonitor::PowerMessageWindow::~PowerMessageWindow() {
   if (message_hwnd_) {
     DestroyWindow(message_hwnd_);
     UnregisterClass(kWindowClassName, instance_);
   }
 }
 
-void SystemMonitor::PowerMessageWindow::ProcessWmPowerBroadcastMessage(
+void PowerMonitor::PowerMessageWindow::ProcessWmPowerBroadcastMessage(
     int event_id) {
-  SystemMonitor::PowerEvent power_event;
+  PowerMonitor::PowerEvent power_event;
   switch (event_id) {
     case PBT_APMPOWERSTATUSCHANGE:  // The power status changed.
-      power_event = SystemMonitor::POWER_STATE_EVENT;
+      power_event = PowerMonitor::POWER_STATE_EVENT;
       break;
     case PBT_APMRESUMEAUTOMATIC:  // Resume from suspend.
     //case PBT_APMRESUMESUSPEND:  // User-initiated resume from suspend.
                                   // We don't notify for this latter event
                                   // because if it occurs it is always sent as a
                                   // second event after PBT_APMRESUMEAUTOMATIC.
-      power_event = SystemMonitor::RESUME_EVENT;
+      power_event = PowerMonitor::RESUME_EVENT;
       break;
     case PBT_APMSUSPEND:  // System has been suspended.
-      power_event = SystemMonitor::SUSPEND_EVENT;
+      power_event = PowerMonitor::SUSPEND_EVENT;
       break;
     default:
       return;
@@ -80,10 +80,10 @@ void SystemMonitor::PowerMessageWindow::ProcessWmPowerBroadcastMessage(
     // PBT_POWERSETTINGCHANGE - user changed the power settings.
   }
 
-  SystemMonitor::Get()->ProcessPowerMessage(power_event);
+  PowerMonitor::Get()->ProcessPowerEvent(power_event);
 }
 
-LRESULT CALLBACK SystemMonitor::PowerMessageWindow::WndProc(
+LRESULT CALLBACK PowerMonitor::PowerMessageWindow::WndProc(
     HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
   switch (message) {
     case WM_POWERBROADCAST: {
@@ -98,10 +98,10 @@ LRESULT CALLBACK SystemMonitor::PowerMessageWindow::WndProc(
 }
 
 // static
-LRESULT CALLBACK SystemMonitor::PowerMessageWindow::WndProcThunk(
+LRESULT CALLBACK PowerMonitor::PowerMessageWindow::WndProcThunk(
     HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
-  SystemMonitor::PowerMessageWindow* message_hwnd =
-      reinterpret_cast<SystemMonitor::PowerMessageWindow*>(
+  PowerMonitor::PowerMessageWindow* message_hwnd =
+      reinterpret_cast<PowerMonitor::PowerMessageWindow*>(
           GetWindowLongPtr(hwnd, GWLP_USERDATA));
   if (message_hwnd)
     return message_hwnd->WndProc(hwnd, message, wparam, lparam);
diff --git a/base/power_monitor/power_observer.h b/base/power_monitor/power_observer.h
new file mode 100644
index 0000000..6be70bb
--- /dev/null
+++ b/base/power_monitor/power_observer.h
@@ -0,0 +1,31 @@
+// Copyright 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.
+
+#ifndef BASE_POWER_MONITOR_POWER_OBSERVER_H_
+#define BASE_POWER_MONITOR_POWER_OBSERVER_H_
+
+#include "base/base_export.h"
+#include "base/compiler_specific.h"
+
+namespace base {
+
+class BASE_EXPORT PowerObserver {
+ public:
+  // Notification of a change in power status of the computer, such
+  // as from switching between battery and A/C power.
+  virtual void OnPowerStateChange(bool on_battery_power) {};
+
+  // Notification that the system is suspending.
+  virtual void OnSuspend() {}
+
+  // Notification that the system is resuming.
+  virtual void OnResume() {}
+
+ protected:
+  virtual ~PowerObserver() {}
+};
+
+}  // namespace base
+
+#endif  // BASE_POWER_MONITOR_POWER_OBSERVER_H_
diff --git a/base/system_monitor/system_monitor.cc b/base/system_monitor/system_monitor.cc
index 7c960cc..b934139 100644
--- a/base/system_monitor/system_monitor.cc
+++ b/base/system_monitor/system_monitor.cc
@@ -14,36 +14,14 @@ namespace base {
 
 static SystemMonitor* g_system_monitor = NULL;
 
-#if defined(ENABLE_BATTERY_MONITORING)
-// The amount of time (in ms) to wait before running the initial
-// battery check.
-static int kDelayedBatteryCheckMs = 10 * 1000;
-#endif  // defined(ENABLE_BATTERY_MONITORING)
-
 SystemMonitor::SystemMonitor()
-    : power_observer_list_(new ObserverListThreadSafe<PowerObserver>()),
-      devices_changed_observer_list_(
-          new ObserverListThreadSafe<DevicesChangedObserver>()),
-      battery_in_use_(false),
-      suspended_(false) {
+    :  devices_changed_observer_list_(
+          new ObserverListThreadSafe<DevicesChangedObserver>()) {
   DCHECK(!g_system_monitor);
   g_system_monitor = this;
-
-  DCHECK(MessageLoop::current());
-#if defined(ENABLE_BATTERY_MONITORING)
-  delayed_battery_check_.Start(FROM_HERE,
-      base::TimeDelta::FromMilliseconds(kDelayedBatteryCheckMs), this,
-      &SystemMonitor::BatteryCheck);
-#endif  // defined(ENABLE_BATTERY_MONITORING)
-#if defined(OS_MACOSX)
-  PlatformInit();
-#endif
 }
 
 SystemMonitor::~SystemMonitor() {
-#if defined(OS_MACOSX)
-  PlatformDestroy();
-#endif
   DCHECK_EQ(this, g_system_monitor);
   g_system_monitor = NULL;
 }
@@ -53,46 +31,10 @@ SystemMonitor* SystemMonitor::Get() {
   return g_system_monitor;
 }
 
-void SystemMonitor::ProcessPowerMessage(PowerEvent event_id) {
-  // Suppress duplicate notifications.  Some platforms may
-  // send multiple notifications of the same event.
-  switch (event_id) {
-    case POWER_STATE_EVENT:
-      {
-        bool on_battery = IsBatteryPower();
-        if (on_battery != battery_in_use_) {
-          battery_in_use_ = on_battery;
-          NotifyPowerStateChange();
-        }
-      }
-      break;
-    case RESUME_EVENT:
-      if (suspended_) {
-        suspended_ = false;
-        NotifyResume();
-      }
-      break;
-    case SUSPEND_EVENT:
-      if (!suspended_) {
-        suspended_ = true;
-        NotifySuspend();
-      }
-      break;
-  }
-}
-
 void SystemMonitor::ProcessDevicesChanged(DeviceType device_type) {
   NotifyDevicesChanged(device_type);
 }
 
-void SystemMonitor::AddPowerObserver(PowerObserver* obs) {
-  power_observer_list_->AddObserver(obs);
-}
-
-void SystemMonitor::RemovePowerObserver(PowerObserver* obs) {
-  power_observer_list_->RemoveObserver(obs);
-}
-
 void SystemMonitor::AddDevicesChangedObserver(DevicesChangedObserver* obs) {
   devices_changed_observer_list_->AddObserver(obs);
 }
@@ -107,25 +49,4 @@ void SystemMonitor::NotifyDevicesChanged(DeviceType device_type) {
       &DevicesChangedObserver::OnDevicesChanged, device_type);
 }
 
-void SystemMonitor::NotifyPowerStateChange() {
-  DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
-           << " battery";
-  power_observer_list_->Notify(&PowerObserver::OnPowerStateChange,
-                               BatteryPower());
-}
-
-void SystemMonitor::NotifySuspend() {
-  DVLOG(1) << "Power Suspending";
-  power_observer_list_->Notify(&PowerObserver::OnSuspend);
-}
-
-void SystemMonitor::NotifyResume() {
-  DVLOG(1) << "Power Resuming";
-  power_observer_list_->Notify(&PowerObserver::OnResume);
-}
-
-void SystemMonitor::BatteryCheck() {
-  ProcessPowerMessage(SystemMonitor::POWER_STATE_EVENT);
-}
-
 }  // namespace base
diff --git a/base/system_monitor/system_monitor.h b/base/system_monitor/system_monitor.h
index 10f279f..5dd849f 100644
--- a/base/system_monitor/system_monitor.h
+++ b/base/system_monitor/system_monitor.h
@@ -5,35 +5,11 @@
 #ifndef BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
 #define BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
 
-#include <map>
-#include <string>
-#include <vector>
-
 #include "base/base_export.h"
 #include "base/basictypes.h"
-#include "build/build_config.h"
-
-// Windows HiRes timers drain the battery faster so we need to know the battery
-// status.  This isn't true for other platforms.
-#if defined(OS_WIN)
-#define ENABLE_BATTERY_MONITORING 1
-#else
-#undef ENABLE_BATTERY_MONITORING
-#endif  // !OS_WIN
-
+#include "base/memory/ref_counted.h"
 #include "base/observer_list_threadsafe.h"
-#if defined(ENABLE_BATTERY_MONITORING)
-#include "base/timer.h"
-#endif  // defined(ENABLE_BATTERY_MONITORING)
-
-#if defined(OS_MACOSX) && !defined(OS_IOS)
-#include <IOKit/pwr_mgt/IOPMLib.h>
-#include <IOKit/IOMessage.h>
-#endif  // OS_MACOSX && !OS_IOS
-
-#if defined(OS_IOS)
-#include <objc/runtime.h>
-#endif  // OS_IOS
+#include "build/build_config.h"
 
 namespace base {
 
@@ -42,13 +18,6 @@ namespace base {
 // TODO(mbelshe):  Add support beyond just power management.
 class BASE_EXPORT SystemMonitor {
  public:
-  // Normalized list of power events.
-  enum PowerEvent {
-    POWER_STATE_EVENT,  // The Power status of the system has changed.
-    SUSPEND_EVENT,      // The system is being suspended.
-    RESUME_EVENT        // The system is being resumed.
-  };
-
   // Type of devices whose change need to be monitored, such as add/remove.
   enum DeviceType {
     DEVTYPE_AUDIO_CAPTURE,  // Audio capture device, e.g., microphone.
@@ -64,50 +33,6 @@ class BASE_EXPORT SystemMonitor {
   // Get the application-wide SystemMonitor (if not present, returns NULL).
   static SystemMonitor* Get();
 
-#if defined(OS_MACOSX)
-  // Allocate system resources needed by the SystemMonitor class.
-  //
-  // This function must be called before instantiating an instance of the class
-  // and before the Sandbox is initialized.
-#if !defined(OS_IOS)
-  static void AllocateSystemIOPorts();
-#else
-  static void AllocateSystemIOPorts() {}
-#endif  // OS_IOS
-#endif  // OS_MACOSX
-
-  //
-  // Power-related APIs
-  //
-
-  // Is the computer currently on battery power.
-  // Can be called on any thread.
-  bool BatteryPower() const {
-    // Using a lock here is not necessary for just a bool.
-    return battery_in_use_;
-  }
-
-  // Callbacks will be called on the thread which creates the SystemMonitor.
-  // During the callback, Add/RemoveObserver will block until the callbacks
-  // are finished. Observers should implement quick callback functions; if
-  // lengthy operations are needed, the observer should take care to invoke
-  // the operation on an appropriate thread.
-  class BASE_EXPORT PowerObserver {
-   public:
-    // Notification of a change in power status of the computer, such
-    // as from switching between battery and A/C power.
-    virtual void OnPowerStateChange(bool on_battery_power) {}
-
-    // Notification that the system is suspending.
-    virtual void OnSuspend() {}
-
-    // Notification that the system is resuming.
-    virtual void OnResume() {}
-
-   protected:
-    virtual ~PowerObserver() {}
-  };
-
   class BASE_EXPORT DevicesChangedObserver {
    public:
     // Notification that the devices connected to the system have changed.
@@ -121,87 +46,26 @@ class BASE_EXPORT SystemMonitor {
   // Add a new observer.
   // Can be called from any thread.
   // Must not be called from within a notification callback.
-  void AddPowerObserver(PowerObserver* obs);
   void AddDevicesChangedObserver(DevicesChangedObserver* obs);
 
   // Remove an existing observer.
   // Can be called from any thread.
   // Must not be called from within a notification callback.
-  void RemovePowerObserver(PowerObserver* obs);
   void RemoveDevicesChangedObserver(DevicesChangedObserver* obs);
 
   // The ProcessFoo() style methods are a broken pattern and should not
   // be copied. Any significant addition to this class is blocked on
   // refactoring to improve the state of affairs. See http://crbug.com/149059
 
-  // Cross-platform handling of a power event.
-  void ProcessPowerMessage(PowerEvent event_id);
-
   // Cross-platform handling of a device change event.
   void ProcessDevicesChanged(DeviceType device_type);
 
  private:
-#if defined(OS_WIN)
-  // Represents a message-only window for power message handling on Windows.
-  // Only allow SystemMonitor to create it.
-  class PowerMessageWindow {
-   public:
-    PowerMessageWindow();
-    ~PowerMessageWindow();
-
-   private:
-    void ProcessWmPowerBroadcastMessage(int event_id);
-    LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
-                             WPARAM wparam, LPARAM lparam);
-    static LRESULT CALLBACK WndProcThunk(HWND hwnd,
-                                         UINT message,
-                                         WPARAM wparam,
-                                         LPARAM lparam);
-    // Instance of the module containing the window procedure.
-    HMODULE instance_;
-    // A hidden message-only window.
-    HWND message_hwnd_;
-  };
-#endif
-
-#if defined(OS_MACOSX)
-  void PlatformInit();
-  void PlatformDestroy();
-#endif
-
-  // Platform-specific method to check whether the system is currently
-  // running on battery power.  Returns true if running on batteries,
-  // false otherwise.
-  bool IsBatteryPower();
-
-  // Checks the battery status and notifies observers if the battery
-  // status has changed.
-  void BatteryCheck();
-
   // Functions to trigger notifications.
   void NotifyDevicesChanged(DeviceType device_type);
-  void NotifyPowerStateChange();
-  void NotifySuspend();
-  void NotifyResume();
 
-  scoped_refptr<ObserverListThreadSafe<PowerObserver> > power_observer_list_;
   scoped_refptr<ObserverListThreadSafe<DevicesChangedObserver> >
       devices_changed_observer_list_;
-  bool battery_in_use_;
-  bool suspended_;
-
-#if defined(ENABLE_BATTERY_MONITORING)
-  base::OneShotTimer<SystemMonitor> delayed_battery_check_;
-#endif
-
-#if defined(OS_IOS)
-  // Holds pointers to system event notification observers.
-  std::vector<id> notification_observers_;
-#endif
-
-#if defined(OS_WIN)
-  PowerMessageWindow power_message_window_;
-#endif
 
   DISALLOW_COPY_AND_ASSIGN(SystemMonitor);
 };
diff --git a/base/system_monitor/system_monitor_android.cc b/base/system_monitor/system_monitor_android.cc
deleted file mode 100644
index f29b7b0..0000000
--- a/base/system_monitor/system_monitor_android.cc
+++ /dev/null
@@ -1,36 +0,0 @@
-// Copyright (c) 2011 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 "base/system_monitor/system_monitor.h"
-#include "jni/SystemMonitor_jni.h"
-
-namespace base {
-
-namespace android {
-
-// Native implementation of SystemMonitor.java.
-void OnBatteryChargingChanged(JNIEnv* env, jclass clazz) {
-  SystemMonitor::Get()->ProcessPowerMessage(SystemMonitor::POWER_STATE_EVENT);
-}
-
-void OnMainActivityResumed(JNIEnv* env, jclass clazz) {
-  SystemMonitor::Get()->ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
-}
-
-void OnMainActivitySuspended(JNIEnv* env, jclass clazz) {
-  SystemMonitor::Get()->ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
-}
-
-}  // namespace android
-
-bool SystemMonitor::IsBatteryPower() {
-  JNIEnv* env = base::android::AttachCurrentThread();
-  return base::android::Java_SystemMonitor_isBatteryPower(env);
-}
-
-bool RegisterSystemMonitor(JNIEnv* env) {
-  return base::android::RegisterNativesImpl(env);
-}
-
-}  // namespace base
diff --git a/base/system_monitor/system_monitor_android.h b/base/system_monitor/system_monitor_android.h
deleted file mode 100644
index 9f60560..0000000
--- a/base/system_monitor/system_monitor_android.h
+++ /dev/null
@@ -1,17 +0,0 @@
-// Copyright (c) 2012 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.
-
-#ifndef BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_ANDROID_H_
-#define BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_ANDROID_H_
-
-#include <jni.h>
-
-namespace base {
-
-// Registers the JNI bindings for SystemMonitor.
-bool RegisterSystemMonitor(JNIEnv* env);
-
-}  // namespace base
-
-#endif  // BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_ANDROID_H_
diff --git a/base/system_monitor/system_monitor_unittest.cc b/base/system_monitor/system_monitor_unittest.cc
index 43f1dd6..b46e52f 100644
--- a/base/system_monitor/system_monitor_unittest.cc
+++ b/base/system_monitor/system_monitor_unittest.cc
@@ -14,45 +14,9 @@ namespace base {
 
 namespace {
 
-class PowerTest : public SystemMonitor::PowerObserver {
- public:
-  PowerTest()
-      : power_state_changes_(0),
-        suspends_(0),
-        resumes_(0) {
-  }
-
-  // PowerObserver callbacks.
-  virtual void OnPowerStateChange(bool on_battery_power) OVERRIDE {
-    power_state_changes_++;
-  }
-
-  virtual void OnSuspend() OVERRIDE {
-    suspends_++;
-  }
-
-  virtual void OnResume() OVERRIDE {
-    resumes_++;
-  }
-
-  // Test status counts.
-  int power_state_changes() { return power_state_changes_; }
-  int suspends() { return suspends_; }
-  int resumes() { return resumes_; }
-
- private:
-  int power_state_changes_;  // Count of OnPowerStateChange notifications.
-  int suspends_;  // Count of OnSuspend notifications.
-  int resumes_;  // Count of OnResume notifications.
-};
-
 class SystemMonitorTest : public testing::Test {
  protected:
   SystemMonitorTest() {
-#if defined(OS_MACOSX)
-    // This needs to happen before SystemMonitor's ctor.
-    SystemMonitor::AllocateSystemIOPorts();
-#endif
     system_monitor_.reset(new SystemMonitor);
   }
   virtual ~SystemMonitorTest() {}
@@ -63,46 +27,6 @@ class SystemMonitorTest : public testing::Test {
   DISALLOW_COPY_AND_ASSIGN(SystemMonitorTest);
 };
 
-TEST_F(SystemMonitorTest, PowerNotifications) {
-  const int kObservers = 5;
-
-  PowerTest test[kObservers];
-  for (int index = 0; index < kObservers; ++index)
-    system_monitor_->AddPowerObserver(&test[index]);
-
-  // Send a bunch of power changes.  Since the battery power hasn't
-  // actually changed, we shouldn't get notifications.
-  for (int index = 0; index < 5; index++) {
-    system_monitor_->ProcessPowerMessage(SystemMonitor::POWER_STATE_EVENT);
-    EXPECT_EQ(test[0].power_state_changes(), 0);
-  }
-
-  // Sending resume when not suspended should have no effect.
-  system_monitor_->ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
-  RunLoop().RunUntilIdle();
-  EXPECT_EQ(test[0].resumes(), 0);
-
-  // Pretend we suspended.
-  system_monitor_->ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
-  RunLoop().RunUntilIdle();
-  EXPECT_EQ(test[0].suspends(), 1);
-
-  // Send a second suspend notification.  This should be suppressed.
-  system_monitor_->ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
-  RunLoop().RunUntilIdle();
-  EXPECT_EQ(test[0].suspends(), 1);
-
-  // Pretend we were awakened.
-  system_monitor_->ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
-  RunLoop().RunUntilIdle();
-  EXPECT_EQ(test[0].resumes(), 1);
-
-  // Send a duplicate resume notification.  This should be suppressed.
-  system_monitor_->ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
-  RunLoop().RunUntilIdle();
-  EXPECT_EQ(test[0].resumes(), 1);
-}
-
 TEST_F(SystemMonitorTest, DeviceChangeNotifications) {
   const int kObservers = 5;
 
diff --git a/build/android/findbugs_filter/findbugs_known_bugs.txt b/build/android/findbugs_filter/findbugs_known_bugs.txt
index 5adce22..61fc567 100644
--- a/build/android/findbugs_filter/findbugs_known_bugs.txt
+++ b/build/android/findbugs_filter/findbugs_known_bugs.txt
@@ -32,7 +32,6 @@ M D SF: Switch statement found in org.chromium.content.browser.ContentSettings$E
 M D SF: Switch statement found in org.chromium.content.browser.HandleView.onTouchEvent(MotionEvent) where default case is missing  At HandleView.java
 M D SF: Switch statement found in org.chromium.content.browser.third_party.GestureDetector.onTouchEvent(MotionEvent) where default case is missing  At GestureDetector.java
 M D ST: Write to static field org.chromium.content.browser.ContentSettings.sAppCachePathIsSet from instance method org.chromium.content.browser.ContentSettings.setAppCachePath(String)  At ContentSettings.java
-M M LI: Incorrect lazy initialization and update of static field org.chromium.base.SystemMonitor.sInstance in org.chromium.base.SystemMonitor.create(Context)  At SystemMonitor.java
 M M LI: Incorrect lazy initialization and update of static field org.chromium.content.browser.ContentVideoView.sContentVideoView in org.chromium.content.browser.ContentVideoView.createContentVideoView(int)  At ContentVideoView.java
 M M UG: org.chromium.content.browser.JavaBridgeReturnValuesTest$TestObject.getBooleanValue() is unsynchronized, org.chromium.content.browser.JavaBridgeReturnValuesTest$TestObject.setBooleanValue(boolean) is synchronized  At JavaBridgeReturnValuesTest.java
 M M UG: org.chromium.content.browser.JavaBridgeReturnValuesTest$TestObject.getStringValue() is unsynchronized, org.chromium.content.browser.JavaBridgeReturnValuesTest$TestObject.setStringValue(String) is synchronized  At JavaBridgeReturnValuesTest.java
diff --git a/chrome/browser/extensions/event_router_forwarder_unittest.cc b/chrome/browser/extensions/event_router_forwarder_unittest.cc
index 1e14b98..975d986 100644
--- a/chrome/browser/extensions/event_router_forwarder_unittest.cc
+++ b/chrome/browser/extensions/event_router_forwarder_unittest.cc
@@ -6,7 +6,7 @@
 
 #include "base/bind.h"
 #include "base/message_loop.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/test/thread_test_helper.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/test/base/testing_browser_process.h"
@@ -92,9 +92,9 @@ class EventRouterForwarderTest : public testing::Test {
         profile_manager_(
             TestingBrowserProcess::GetGlobal()) {
 #if defined(OS_MACOSX)
-    base::SystemMonitor::AllocateSystemIOPorts();
+    base::PowerMonitor::AllocateSystemIOPorts();
 #endif
-    dummy.reset(new base::SystemMonitor);
+    dummy.reset(new base::PowerMonitor);
   }
 
   virtual void SetUp() {
@@ -118,7 +118,7 @@ class EventRouterForwarderTest : public testing::Test {
   content::TestBrowserThread ui_thread_;
   content::TestBrowserThread io_thread_;
   TestingProfileManager profile_manager_;
-  scoped_ptr<base::SystemMonitor> dummy;
+  scoped_ptr<base::PowerMonitor> dummy;
   // Profiles are weak pointers, owned by ProfileManager in |browser_process_|.
   TestingProfile* profile1_;
   TestingProfile* profile2_;
diff --git a/chrome/browser/profiles/profile_manager_unittest.cc b/chrome/browser/profiles/profile_manager_unittest.cc
index c8f01c6..ebc8b58 100644
--- a/chrome/browser/profiles/profile_manager_unittest.cc
+++ b/chrome/browser/profiles/profile_manager_unittest.cc
@@ -9,7 +9,6 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
-#include "base/system_monitor/system_monitor.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "build/build_config.h"
@@ -98,10 +97,6 @@ class ProfileManagerTest : public testing::Test {
         file_thread_(BrowserThread::FILE, &message_loop_),
         io_thread_(local_state_.Get(), g_browser_process->policy_service(),
                    NULL, extension_event_router_forwarder_) {
-#if defined(OS_MACOSX)
-    base::SystemMonitor::AllocateSystemIOPorts();
-#endif
-    system_monitor_dummy_.reset(new base::SystemMonitor);
     TestingBrowserProcess::GetGlobal()->SetIOThread(&io_thread_);
   }
 
@@ -141,8 +136,6 @@ class ProfileManagerTest : public testing::Test {
   content::TestBrowserThread file_thread_;
   // IOThread is necessary for the creation of some services below.
   IOThread io_thread_;
-
-  scoped_ptr<base::SystemMonitor> system_monitor_dummy_;
 };
 
 TEST_F(ProfileManagerTest, GetProfile) {
diff --git a/chrome/nacl/nacl_exe_win_64.cc b/chrome/nacl/nacl_exe_win_64.cc
index 0a3f9e4..f0cb832 100644
--- a/chrome/nacl/nacl_exe_win_64.cc
+++ b/chrome/nacl/nacl_exe_win_64.cc
@@ -7,9 +7,9 @@
 #include "base/hi_res_timer_manager.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/process_util.h"
 #include "base/string_util.h"
-#include "base/system_monitor/system_monitor.h"
 #include "chrome/app/breakpad_win.h"
 #include "chrome/common/chrome_result_codes.h"
 #include "chrome/common/chrome_switches.h"
@@ -32,7 +32,7 @@ int NaClBrokerMain(const content::MainFunctionParams& parameters) {
   MessageLoopForIO main_message_loop;
   base::PlatformThread::SetName("CrNaClBrokerMain");
 
-  base::SystemMonitor system_monitor;
+  base::PowerMonitor power_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
   NaClBrokerListener listener;
diff --git a/chrome/nacl/nacl_main.cc b/chrome/nacl/nacl_main.cc
index e340b38..9b7a8c6 100644
--- a/chrome/nacl/nacl_main.cc
+++ b/chrome/nacl/nacl_main.cc
@@ -7,7 +7,7 @@
 #include "base/command_line.h"
 #include "base/hi_res_timer_manager.h"
 #include "base/message_loop.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 #include "chrome/common/chrome_result_codes.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
@@ -23,7 +23,7 @@ int NaClMain(const content::MainFunctionParams& parameters) {
   MessageLoopForIO main_message_loop;
   base::PlatformThread::SetName("CrNaClMain");
 
-  base::SystemMonitor system_monitor;
+  base::PowerMonitor power_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
diff --git a/content/app/content_main_runner.cc b/content/app/content_main_runner.cc
index 6630446..256f78f 100644
--- a/content/app/content_main_runner.cc
+++ b/content/app/content_main_runner.cc
@@ -67,7 +67,7 @@
 #include "base/mac/scoped_nsautorelease_pool.h"
 #if !defined(OS_IOS)
 #include "base/mach_ipc_mac.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 #include "content/browser/mach_broker_mac.h"
 #include "content/common/sandbox_init_mac.h"
 #endif  // !OS_IOS
@@ -651,9 +651,9 @@ class ContentMainRunnerImpl : public ContentMainRunner {
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
     // We need to allocate the IO Ports before the Sandbox is initialized or
-    // the first instance of SystemMonitor is created.
+    // the first instance of PowerMonitor is created.
     // It's important not to allocate the ports for processes which don't
-    // register with the system monitor - see crbug.com/88867.
+    // register with the power monitor - see crbug.com/88867.
     if (process_type.empty() ||
         process_type == switches::kPluginProcess ||
         process_type == switches::kRendererProcess ||
@@ -661,7 +661,7 @@ class ContentMainRunnerImpl : public ContentMainRunner {
         process_type == switches::kWorkerProcess ||
         (delegate &&
          delegate->ProcessRegistersWithSystemProcess(process_type))) {
-      base::SystemMonitor::AllocateSystemIOPorts();
+      base::PowerMonitor::AllocateSystemIOPorts();
     }
 
     if (!process_type.empty() &&
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index e85329f..713cdbf 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -13,6 +13,8 @@
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/pending_task.h"
+#include "base/power_monitor/power_monitor.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/run_loop.h"
 #include "base/string_number_conversions.h"
 #include "base/threading/thread_restrictions.h"
@@ -367,6 +369,7 @@ void BrowserMainLoop::MainMessageLoopStart() {
   InitializeMainThread();
 
   system_monitor_.reset(new base::SystemMonitor);
+  power_monitor_.reset(new base::PowerMonitor);
   hi_res_timer_manager_.reset(new HighResolutionTimerManager);
   network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
   audio_manager_.reset(media::AudioManager::Create());
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index 9118309..30442a6 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -14,6 +14,7 @@ class HighResolutionTimerManager;
 
 namespace base {
 class MessageLoop;
+class PowerMonitor;
 class SystemMonitor;
 }
 
@@ -95,6 +96,7 @@ class BrowserMainLoop {
   // Members initialized in |MainMessageLoopStart()| ---------------------------
   scoped_ptr<base::MessageLoop> main_message_loop_;
   scoped_ptr<base::SystemMonitor> system_monitor_;
+  scoped_ptr<base::PowerMonitor> power_monitor_;
   scoped_ptr<HighResolutionTimerManager> hi_res_timer_manager_;
   scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
   scoped_ptr<media::AudioManager> audio_manager_;
diff --git a/content/browser/gamepad/gamepad_test_helpers.cc b/content/browser/gamepad/gamepad_test_helpers.cc
index abf4187..e4db14c 100644
--- a/content/browser/gamepad/gamepad_test_helpers.cc
+++ b/content/browser/gamepad/gamepad_test_helpers.cc
@@ -4,7 +4,6 @@
 
 #include "content/browser/gamepad/gamepad_test_helpers.h"
 
-#include "base/system_monitor/system_monitor.h"
 #include "content/browser/gamepad/gamepad_service.h"
 
 namespace content {
@@ -37,10 +36,6 @@ void MockGamepadDataFetcher::SetTestData(const WebKit::WebGamepads& new_data) {
 }
 
 GamepadTestHelper::GamepadTestHelper() {
-#if defined(OS_MACOSX)
-  base::SystemMonitor::AllocateSystemIOPorts();
-#endif
-  system_monitor_.reset(new base::SystemMonitor);
 }
 
 GamepadTestHelper::~GamepadTestHelper() {
diff --git a/content/browser/gamepad/gamepad_test_helpers.h b/content/browser/gamepad/gamepad_test_helpers.h
index 9abba01..6b97eda 100644
--- a/content/browser/gamepad/gamepad_test_helpers.h
+++ b/content/browser/gamepad/gamepad_test_helpers.h
@@ -12,10 +12,6 @@
 #include "content/browser/gamepad/gamepad_data_fetcher.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGamepads.h"
 
-namespace base {
-class SystemMonitor;
-}
-
 namespace content {
 
 class GamepadService;
@@ -60,8 +56,6 @@ class GamepadTestHelper {
   // This must be constructed before the system monitor.
   MessageLoop message_loop_;
 
-  scoped_ptr<base::SystemMonitor> system_monitor_;
-
   DISALLOW_COPY_AND_ASSIGN(GamepadTestHelper);
 };
 
diff --git a/content/plugin/plugin_main.cc b/content/plugin/plugin_main.cc
index 971e308..2f0817e 100644
--- a/content/plugin/plugin_main.cc
+++ b/content/plugin/plugin_main.cc
@@ -13,7 +13,7 @@
 #include "base/hi_res_timer_manager.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/threading/platform_thread.h"
 #include "content/common/child_process.h"
 #include "content/plugin/plugin_thread.h"
@@ -55,7 +55,7 @@ int PluginMain(const MainFunctionParams& parameters) {
   MessageLoop main_message_loop(MessageLoop::TYPE_UI);
   base::PlatformThread::SetName("CrPluginMain");
 
-  base::SystemMonitor system_monitor;
+  base::PowerMonitor power_monitor;
   HighResolutionTimerManager high_resolution_timer_manager;
 
   const CommandLine& parsed_command_line = parameters.command_line;
diff --git a/content/public/test/browser_test_base.cc b/content/public/test/browser_test_base.cc
index 04d6ff0..4d44268 100644
--- a/content/public/test/browser_test_base.cc
+++ b/content/public/test/browser_test_base.cc
@@ -13,7 +13,7 @@
 
 #if defined(OS_MACOSX)
 #include "base/mac/mac_util.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 #endif
 
 #if defined(OS_ANDROID)
@@ -52,7 +52,7 @@ extern int BrowserMain(const content::MainFunctionParams&);
 BrowserTestBase::BrowserTestBase() {
 #if defined(OS_MACOSX)
   base::mac::SetOverrideAmIBundled(true);
-  base::SystemMonitor::AllocateSystemIOPorts();
+  base::PowerMonitor::AllocateSystemIOPorts();
 #endif
 
 #if defined(OS_POSIX)
diff --git a/content/renderer/renderer_main.cc b/content/renderer/renderer_main.cc
index 7cfd127..c154e69c 100644
--- a/content/renderer/renderer_main.cc
+++ b/content/renderer/renderer_main.cc
@@ -17,9 +17,9 @@
 #include "base/metrics/stats_counters.h"
 #include "base/path_service.h"
 #include "base/pending_task.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/process_util.h"
 #include "base/string_util.h"
-#include "base/system_monitor/system_monitor.h"
 #include "base/threading/platform_thread.h"
 #include "base/time.h"
 #include "content/common/pepper_plugin_registry.h"
@@ -161,7 +161,7 @@ int RendererMain(const MainFunctionParams& parameters) {
 
   base::PlatformThread::SetName("CrRendererMain");
 
-  base::SystemMonitor system_monitor;
+  base::PowerMonitor power_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
   platform.PlatformInitialize();
diff --git a/content/utility/utility_main.cc b/content/utility/utility_main.cc
index 549af2c..8257c09 100644
--- a/content/utility/utility_main.cc
+++ b/content/utility/utility_main.cc
@@ -5,7 +5,7 @@
 #include "base/command_line.h"
 #include "base/hi_res_timer_manager.h"
 #include "base/message_loop.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/threading/platform_thread.h"
 #include "content/common/child_process.h"
 #include "content/public/common/content_switches.h"
@@ -25,7 +25,7 @@ int UtilityMain(const MainFunctionParams& parameters) {
   MessageLoop main_message_loop;
   base::PlatformThread::SetName("CrUtilityMain");
 
-  base::SystemMonitor system_monitor;
+  base::PowerMonitor power_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
 #if defined(OS_LINUX)
diff --git a/content/worker/worker_main.cc b/content/worker/worker_main.cc
index 192cc57..981d0a5 100644
--- a/content/worker/worker_main.cc
+++ b/content/worker/worker_main.cc
@@ -6,8 +6,8 @@
 #include "base/command_line.h"
 #include "base/hi_res_timer_manager.h"
 #include "base/message_loop.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/string_util.h"
-#include "base/system_monitor/system_monitor.h"
 #include "base/threading/platform_thread.h"
 #include "content/common/child_process.h"
 #include "content/public/common/main_function_params.h"
@@ -30,7 +30,7 @@ int WorkerMain(const MainFunctionParams& parameters) {
   MessageLoop main_message_loop;
   base::PlatformThread::SetName("CrWorkerMain");
 
-  base::SystemMonitor system_monitor;
+  base::PowerMonitor power_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
 #if defined(OS_WIN)
diff --git a/net/http/http_network_layer.h b/net/http/http_network_layer.h
index 63507b4..4b41b71 100644
--- a/net/http/http_network_layer.h
+++ b/net/http/http_network_layer.h
@@ -9,7 +9,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/power_monitor/power_observer.h"
 #include "base/threading/non_thread_safe.h"
 #include "net/base/net_export.h"
 #include "net/http/http_transaction_factory.h"
@@ -20,7 +20,7 @@ class HttpNetworkSession;
 
 class NET_EXPORT HttpNetworkLayer
     : public HttpTransactionFactory,
-      public base::SystemMonitor::PowerObserver,
+      public base::PowerObserver,
       NON_EXPORTED_BASE(public base::NonThreadSafe) {
  public:
   // Construct a HttpNetworkLayer with an existing HttpNetworkSession which
@@ -47,7 +47,7 @@ class NET_EXPORT HttpNetworkLayer
   virtual HttpCache* GetCache() OVERRIDE;
   virtual HttpNetworkSession* GetSession() OVERRIDE;
 
-  // base::SystemMonitor::PowerObserver methods:
+  // base::PowerObserver methods:
   virtual void OnSuspend() OVERRIDE;
   virtual void OnResume() OVERRIDE;
 
diff --git a/net/url_request/url_request_job.cc b/net/url_request/url_request_job.cc
index 3c470a4..752c50f 100644
--- a/net/url_request/url_request_job.cc
+++ b/net/url_request/url_request_job.cc
@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop.h"
+#include "base/power_monitor/power_monitor.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "net/base/auth.h"
@@ -34,9 +35,9 @@ URLRequestJob::URLRequestJob(URLRequest* request,
       deferred_redirect_status_code_(-1),
       network_delegate_(network_delegate),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {
-  base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
-  if (system_monitor)
-    base::SystemMonitor::Get()->AddPowerObserver(this);
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  if (power_monitor)
+    power_monitor->AddObserver(this);
 }
 
 void URLRequestJob::SetUpload(UploadDataStream* upload) {
@@ -229,9 +230,9 @@ void URLRequestJob::NotifyURLRequestDestroyed() {
 }
 
 URLRequestJob::~URLRequestJob() {
-  base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
-  if (system_monitor)
-    base::SystemMonitor::Get()->RemovePowerObserver(this);
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  if (power_monitor)
+    power_monitor->RemoveObserver(this);
 }
 
 void URLRequestJob::NotifyCertificateRequested(
diff --git a/net/url_request/url_request_job.h b/net/url_request/url_request_job.h
index ae95673..bd78ef5 100644
--- a/net/url_request/url_request_job.h
+++ b/net/url_request/url_request_job.h
@@ -11,7 +11,8 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
-#include "base/system_monitor/system_monitor.h"
+#include "base/message_loop.h"
+#include "base/power_monitor/power_observer.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/filter.h"
 #include "net/base/host_port_pair.h"
@@ -38,8 +39,9 @@ class UploadDataStream;
 class URLRequestStatus;
 class X509Certificate;
 
-class NET_EXPORT URLRequestJob : public base::RefCounted<URLRequestJob>,
-                                 public base::SystemMonitor::PowerObserver {
+class NET_EXPORT URLRequestJob
+    : public base::RefCounted<URLRequestJob>,
+      public base::PowerObserver {
  public:
   explicit URLRequestJob(URLRequest* request,
                          NetworkDelegate* network_delegate);
@@ -195,7 +197,7 @@ class NET_EXPORT URLRequestJob : public base::RefCounted<URLRequestJob>,
   // See url_request.h for details.
   virtual HostPortPair GetSocketAddress() const;
 
-  // base::SystemMonitor::PowerObserver methods:
+  // base::PowerObserver methods:
   // We invoke URLRequestJob::Kill on suspend (crbug.com/4606).
   virtual void OnSuspend() OVERRIDE;
 
diff --git a/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java b/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java
index 21b0f85..d15d04e 100644
--- a/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java
+++ b/testing/android/java/src/org/chromium/native_test/ChromeNativeTestActivity.java
@@ -13,7 +13,7 @@ import android.util.Log;
 
 import org.chromium.base.ChromiumActivity;
 import org.chromium.base.PathUtils;
-import org.chromium.base.SystemMonitor;
+import org.chromium.base.PowerMonitor;
 
 import java.io.File;
 
@@ -43,7 +43,7 @@ public class ChromeNativeTestActivity extends ChromiumActivity {
         PathUtils.setPrivateDataDirectorySuffix("chrome");
 
         // Needed by system_monitor_unittest.cc
-        SystemMonitor.createForTests(this);
+        PowerMonitor.createForTests(this);
 
 
         loadLibrary();
diff --git a/webkit/blob/blob_url_request_job.h b/webkit/blob/blob_url_request_job.h
index e24a491..00463be 100644
--- a/webkit/blob/blob_url_request_job.h
+++ b/webkit/blob/blob_url_request_job.h
@@ -5,6 +5,8 @@
 #ifndef WEBKIT_BLOB_BLOB_URL_REQUEST_JOB_H_
 #define WEBKIT_BLOB_BLOB_URL_REQUEST_JOB_H_
 
+#include <map>
+
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/platform_file.h"