Move SystemMonitor to base/.

I plan to use SystemMonitor in net/.

Fix up the Mac implementation not to use Cocoa APIs since @interface is not allowed in base.

BUG=none
TEST=none

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=85732

Review URL: http://codereview.chromium.org/7015017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85737 0039d316-1c4b-4281-b951-d872f2087c98

28 files changed, 534 insertions, 51 deletions

diff --git a/app/app.gyp b/app/app.gyp
index 955a6d6..e639728 100644
--- a/app/app.gyp
+++ b/app/app.gyp
@@ -41,7 +41,6 @@
         '../ui/base/models/tree_node_model_unittest.cc',
         '../ui/base/resource/data_pack_unittest.cc',
         '../ui/base/resource/resource_bundle_unittest.cc',
-        '../ui/base/system_monitor/system_monitor_unittest.cc',
         '../ui/base/test/data/resource.h',
         '../ui/base/text/text_elider_unittest.cc',
         '../ui/base/view_prop_unittest.cc',
diff --git a/app/app_base.gypi b/app/app_base.gypi
index 82c3962..a52e391 100644
--- a/app/app_base.gypi
+++ b/app/app_base.gypi
@@ -18,11 +18,6 @@
             '../ui/base/models/tree_model.h',
             '../ui/base/models/tree_node_iterator.h',
             '../ui/base/models/tree_node_model.h',
-            '../ui/base/system_monitor/system_monitor.cc',
-            '../ui/base/system_monitor/system_monitor.h',
-            '../ui/base/system_monitor/system_monitor_mac.mm',
-            '../ui/base/system_monitor/system_monitor_posix.cc',
-            '../ui/base/system_monitor/system_monitor_win.cc',
             '../ui/base/ui_base_paths.h',
             '../ui/base/ui_base_paths.cc',
             '../ui/base/ui_base_switches.h',
diff --git a/base/base.gyp b/base/base.gyp
index 8514894..68974f5 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -186,6 +186,7 @@
         'sys_info_unittest.cc',
         'sys_string_conversions_mac_unittest.mm',
         'sys_string_conversions_unittest.cc',
+        'system_monitor/system_monitor_unittest.cc',
         'task_queue_unittest.cc',
         'task_unittest.cc',
         'template_util_unittest.cc',
@@ -283,7 +284,6 @@
             ['exclude', '^win/'],
           ],
           'sources!': [
-            'system_monitor_unittest.cc',
             'time_win_unittest.cc',
             'trace_event_win_unittest.cc',
             'win_util_unittest.cc',
diff --git a/base/base.gypi b/base/base.gypi
index 56da313..25060bb 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -243,6 +243,11 @@
           'synchronization/waitable_event_watcher_posix.cc',
           'synchronization/waitable_event_watcher_win.cc',
           'synchronization/waitable_event_win.cc',
+          'system_monitor/system_monitor.cc',
+          'system_monitor/system_monitor.h',
+          'system_monitor/system_monitor_mac.mm',
+          'system_monitor/system_monitor_posix.cc',
+          'system_monitor/system_monitor_win.cc',
           'sys_info.h',
           'sys_info_chromeos.cc',
           'sys_info_freebsd.cc',
diff --git a/base/system_monitor/system_monitor.cc b/base/system_monitor/system_monitor.cc
new file mode 100644
index 0000000..7b1349c
--- /dev/null
+++ b/base/system_monitor/system_monitor.cc
@@ -0,0 +1,108 @@
+// 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 "base/logging.h"
+#include "base/message_loop.h"
+#include "base/time.h"
+
+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()
+    : observer_list_(new ObserverListThreadSafe<PowerObserver>()),
+      battery_in_use_(false),
+      suspended_(false) {
+  DCHECK(!g_system_monitor);
+  g_system_monitor = this;
+
+  DCHECK(MessageLoop::current());
+#if defined(ENABLE_BATTERY_MONITORING)
+  delayed_battery_check_.Start(
+      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;
+}
+
+// static
+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::AddObserver(PowerObserver* obs) {
+  observer_list_->AddObserver(obs);
+}
+
+void SystemMonitor::RemoveObserver(PowerObserver* obs) {
+  observer_list_->RemoveObserver(obs);
+}
+
+void SystemMonitor::NotifyPowerStateChange() {
+  VLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
+          << " battery";
+  observer_list_->Notify(&PowerObserver::OnPowerStateChange, BatteryPower());
+}
+
+void SystemMonitor::NotifySuspend() {
+  VLOG(1) << "Power Suspending";
+  observer_list_->Notify(&PowerObserver::OnSuspend);
+}
+
+void SystemMonitor::NotifyResume() {
+  VLOG(1) << "Power Resuming";
+  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
new file mode 100644
index 0000000..e552b26
--- /dev/null
+++ b/base/system_monitor/system_monitor.h
@@ -0,0 +1,142 @@
+// 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.
+
+#ifndef BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
+#define BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
+#pragma once
+
+#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/observer_list_threadsafe.h"
+#if defined(ENABLE_BATTERY_MONITORING)
+#include "base/timer.h"
+#endif  // defined(ENABLE_BATTERY_MONITORING)
+
+#if defined(OS_MACOSX)
+#include <IOKit/pwr_mgt/IOPMLib.h>
+#include <IOKit/IOMessage.h>
+#endif  // OS_MACOSX
+
+namespace base {
+
+// Class for monitoring various system-related subsystems
+// such as power management, network status, etc.
+// TODO(mbelshe):  Add support beyond just power management.
+class 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.
+  };
+
+  // Create SystemMonitor. Only one SystemMonitor instance per application
+  // is allowed.
+  SystemMonitor();
+  ~SystemMonitor();
+
+  // Get the application-wide SystemMonitor (if not present, returns NULL).
+  static SystemMonitor* Get();
+
+  //
+  // 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 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() {}
+  };
+
+  // Add a new observer.
+  // Can be called from any thread.
+  // Must not be called from within a notification callback.
+  void AddObserver(PowerObserver* obs);
+
+  // Remove an existing observer.
+  // Can be called from any thread.
+  // Must not be called from within a notification callback.
+  void RemoveObserver(PowerObserver* obs);
+
+#if defined(OS_WIN)
+  // Windows-specific handling of a WM_POWERBROADCAST message.
+  // Embedders of this API should hook their top-level window
+  // message loop and forward WM_POWERBROADCAST through this call.
+  void ProcessWmPowerBroadcastMessage(int event_id);
+#endif
+
+  // Cross-platform handling of a power event.
+  void ProcessPowerMessage(PowerEvent event_id);
+
+ private:
+#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 NotifyPowerStateChange();
+  void NotifySuspend();
+  void NotifyResume();
+
+  scoped_refptr<ObserverListThreadSafe<PowerObserver> > observer_list_;
+  bool battery_in_use_;
+  bool suspended_;
+
+#if defined(ENABLE_BATTERY_MONITORING)
+  base::OneShotTimer<SystemMonitor> delayed_battery_check_;
+#endif
+
+#if defined(OS_MACOSX)
+  IONotificationPortRef notification_port_ref_;
+  io_object_t notifier_object_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(SystemMonitor);
+};
+
+}  // namespace base
+
+#endif  // BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
diff --git a/base/system_monitor/system_monitor_mac.mm b/base/system_monitor/system_monitor_mac.mm
new file mode 100644
index 0000000..8611613
--- /dev/null
+++ b/base/system_monitor/system_monitor_mac.mm
@@ -0,0 +1,78 @@
+// 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.
+
+// Implementation based on sample code from
+// http://developer.apple.com/library/mac/#qa/qa1340/_index.html.
+
+#include "base/system_monitor/system_monitor.h"
+
+#include <IOKit/pwr_mgt/IOPMLib.h>
+#include <IOKit/IOMessage.h>
+
+namespace base {
+
+namespace {
+
+io_connect_t g_system_power_io_port = 0;
+
+void SystemPowerEventCallback(void* system_monitor,
+                              io_service_t service,
+                              natural_t message_type,
+                              void* message_argument) {
+  DCHECK(system_monitor);
+  SystemMonitor* sys_monitor = reinterpret_cast<SystemMonitor*>(system_monitor);
+  switch (message_type) {
+    case kIOMessageSystemWillSleep:
+      sys_monitor->ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
+      IOAllowPowerChange(g_system_power_io_port,
+          reinterpret_cast<int>(message_argument));
+      break;
+
+    case kIOMessageSystemWillPowerOn:
+      sys_monitor->ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
+      break;
+  }
+}
+
+}  // namespace
+
+void SystemMonitor::PlatformInit() {
+  DCHECK_EQ(g_system_power_io_port, 0u);
+
+  // Notification port allocated by IORegisterForSystemPower.
+
+  g_system_power_io_port = IORegisterForSystemPower(
+      this, &notification_port_ref_, SystemPowerEventCallback,
+      &notifier_object_);
+  DCHECK_NE(g_system_power_io_port, 0u);
+
+  // Add the notification port to the application runloop
+  CFRunLoopAddSource(CFRunLoopGetCurrent(),
+                     IONotificationPortGetRunLoopSource(notification_port_ref_),
+                     kCFRunLoopCommonModes);
+}
+
+void SystemMonitor::PlatformDestroy() {
+  DCHECK_NE(g_system_power_io_port, 0u);
+
+  // Remove the sleep notification port from the application runloop
+  CFRunLoopRemoveSource(
+      CFRunLoopGetCurrent(),
+      IONotificationPortGetRunLoopSource(notification_port_ref_),
+      kCFRunLoopCommonModes);
+
+  // Deregister for system sleep notifications
+  IODeregisterForSystemPower(&notifier_object_);
+
+  // IORegisterForSystemPower implicitly opens the Root Power Domain IOService,
+  // so we close it here.
+  IOServiceClose(g_system_power_io_port);
+
+  g_system_power_io_port = 0;
+
+  // Destroy the notification port allocated by IORegisterForSystemPower.
+  IONotificationPortDestroy(notification_port_ref_);
+}
+
+}  // namespace base
diff --git a/base/system_monitor/system_monitor_posix.cc b/base/system_monitor/system_monitor_posix.cc
new file mode 100644
index 0000000..6cf01bf
--- /dev/null
+++ b/base/system_monitor/system_monitor_posix.cc
@@ -0,0 +1,14 @@
+// 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"
+
+namespace base {
+
+bool SystemMonitor::IsBatteryPower() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
+}  // namespace base
diff --git a/base/system_monitor/system_monitor_unittest.cc b/base/system_monitor/system_monitor_unittest.cc
new file mode 100644
index 0000000..9517247
--- /dev/null
+++ b/base/system_monitor/system_monitor_unittest.cc
@@ -0,0 +1,91 @@
+// 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 "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+class PowerTest : public SystemMonitor::PowerObserver {
+ public:
+  PowerTest()
+      : battery_(false),
+        power_state_changes_(0),
+        suspends_(0),
+        resumes_(0) {
+  }
+
+  // PowerObserver callbacks.
+  void OnPowerStateChange(bool on_battery_power) {
+    power_state_changes_++;
+  }
+
+  void OnSuspend() {
+    suspends_++;
+  }
+
+  void OnResume() {
+    resumes_++;
+  }
+
+  // Test status counts.
+  bool battery() { return battery_; }
+  int power_state_changes() { return power_state_changes_; }
+  int suspends() { return suspends_; }
+  int resumes() { return resumes_; }
+
+ private:
+  bool battery_;   // Do we currently think we're on battery power.
+  int power_state_changes_;  // Count of OnPowerStateChange notifications.
+  int suspends_;  // Count of OnSuspend notifications.
+  int resumes_;  // Count of OnResume notifications.
+};
+
+TEST(SystemMonitor, PowerNotifications) {
+  const int kObservers = 5;
+
+  // Initialize a message loop for this to run on.
+  MessageLoop loop;
+  // Initialize time() since it registers as a SystemMonitor observer.
+  base::Time now = base::Time::Now();
+
+  SystemMonitor system_monitor;
+  PowerTest test[kObservers];
+  for (int index = 0; index < kObservers; ++index)
+    system_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++) {
+    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);
+  loop.RunAllPending();
+  EXPECT_EQ(test[0].resumes(), 0);
+
+  // Pretend we suspended.
+  system_monitor.ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
+  loop.RunAllPending();
+  EXPECT_EQ(test[0].suspends(), 1);
+
+  // Send a second suspend notification.  This should be suppressed.
+  system_monitor.ProcessPowerMessage(SystemMonitor::SUSPEND_EVENT);
+  loop.RunAllPending();
+  EXPECT_EQ(test[0].suspends(), 1);
+
+  // Pretend we were awakened.
+  system_monitor.ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
+  loop.RunAllPending();
+  EXPECT_EQ(test[0].resumes(), 1);
+
+  // Send a duplicate resume notification.  This should be suppressed.
+  system_monitor.ProcessPowerMessage(SystemMonitor::RESUME_EVENT);
+  loop.RunAllPending();
+  EXPECT_EQ(test[0].resumes(), 1);
+}
+
+}  // namespace base
diff --git a/base/system_monitor/system_monitor_win.cc b/base/system_monitor/system_monitor_win.cc
new file mode 100644
index 0000000..84f2b2e
--- /dev/null
+++ b/base/system_monitor/system_monitor_win.cc
@@ -0,0 +1,50 @@
+// 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"
+
+namespace base {
+
+void SystemMonitor::ProcessWmPowerBroadcastMessage(int event_id) {
+  PowerEvent power_event;
+  switch (event_id) {
+    case PBT_APMPOWERSTATUSCHANGE:  // The power status changed.
+      power_event = 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 = RESUME_EVENT;
+      break;
+    case PBT_APMSUSPEND:  // System has been suspended.
+      power_event = SUSPEND_EVENT;
+      break;
+    default:
+      return;
+
+    // Other Power Events:
+    // PBT_APMBATTERYLOW - removed in Vista.
+    // PBT_APMOEMEVENT - removed in Vista.
+    // PBT_APMQUERYSUSPEND - removed in Vista.
+    // PBT_APMQUERYSUSPENDFAILED - removed in Vista.
+    // PBT_APMRESUMECRITICAL - removed in Vista.
+    // PBT_POWERSETTINGCHANGE - user changed the power settings.
+  }
+  ProcessPowerMessage(power_event);
+}
+
+// Function to query the system to see if it is currently running on
+// battery power.  Returns true if running on battery.
+bool SystemMonitor::IsBatteryPower() {
+  SYSTEM_POWER_STATUS status;
+  if (!GetSystemPowerStatus(&status)) {
+    LOG(ERROR) << "GetSystemPowerStatus failed: " << GetLastError();
+    return false;
+  }
+  return (status.ACLineStatus == 0);
+}
+
+}  // namespace base
diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index 57d3618..6f2948e 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -24,6 +24,7 @@
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time.h"
@@ -109,7 +110,6 @@
 #include "net/url_request/url_request_throttler_manager.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
-#include "ui/base/system_monitor/system_monitor.h"
 #include "ui/gfx/gl/gl_implementation.h"
 #include "ui/gfx/gl/gl_switches.h"
 
@@ -527,7 +527,7 @@ void BrowserMainParts::MainMessageLoopStart() {
   main_message_loop_.reset(new MessageLoop(MessageLoop::TYPE_UI));
 
   // TODO(viettrungluu): should these really go before setting the thread name?
-  system_monitor_.reset(new ui::SystemMonitor);
+  system_monitor_.reset(new base::SystemMonitor);
   hi_res_timer_manager_.reset(new HighResolutionTimerManager);
   network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
 
diff --git a/chrome/browser/browser_main.h b/chrome/browser/browser_main.h
index a867e20..09153db 100644
--- a/chrome/browser/browser_main.h
+++ b/chrome/browser/browser_main.h
@@ -20,12 +20,12 @@ class MessageLoop;
 class MetricsService;
 class PrefService;
 
-namespace net {
-class NetworkChangeNotifier;
+namespace base {
+class SystemMonitor;
 }
 
-namespace ui {
-class SystemMonitor;
+namespace net {
+class NetworkChangeNotifier;
 }
 
 // BrowserMainParts:
@@ -166,7 +166,7 @@ class BrowserMainParts {
 
   // Members initialized in |MainMessageLoopStart()| ---------------------------
   scoped_ptr<MessageLoop> main_message_loop_;
-  scoped_ptr<ui::SystemMonitor> system_monitor_;
+  scoped_ptr<base::SystemMonitor> system_monitor_;
   scoped_ptr<HighResolutionTimerManager> hi_res_timer_manager_;
   scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
   scoped_ptr<BrowserThread> main_thread_;
diff --git a/chrome/browser/extensions/extension_event_router_forwarder_unittest.cc b/chrome/browser/extensions/extension_event_router_forwarder_unittest.cc
index 7d82ea5..ff5f5da 100644
--- a/chrome/browser/extensions/extension_event_router_forwarder_unittest.cc
+++ b/chrome/browser/extensions/extension_event_router_forwarder_unittest.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/extensions/extension_event_router_forwarder.h"
 
 #include "base/message_loop.h"
+#include "base/system_monitor/system_monitor.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/test/testing_browser_process_test.h"
 #include "chrome/test/testing_profile.h"
@@ -13,7 +14,6 @@
 #include "googleurl/src/gurl.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "ui/base/system_monitor/system_monitor.h"
 
 namespace {
 
@@ -66,7 +66,7 @@ class ExtensionEventRouterForwarderTest : public TestingBrowserProcessTest {
   MessageLoopForUI message_loop_;
   BrowserThread ui_thread_;
   BrowserThread io_thread_;
-  ui::SystemMonitor dummy;
+  base::SystemMonitor dummy;
   // Profiles are weak pointers, owned by ProfileManager in |browser_process_|.
   TestingProfile* profile1_;
   TestingProfile* profile2_;
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
index cee0265..dbd03de 100644
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -111,7 +111,7 @@ Profile* ProfileManager::GetDefaultProfile() {
 }
 
 ProfileManager::ProfileManager() : logged_in_(false) {
-  ui::SystemMonitor::Get()->AddObserver(this);
+  base::SystemMonitor::Get()->AddObserver(this);
   BrowserList::AddObserver(this);
 #if defined(OS_CHROMEOS)
   registrar_.Add(
@@ -122,7 +122,7 @@ ProfileManager::ProfileManager() : logged_in_(false) {
 }
 
 ProfileManager::~ProfileManager() {
-  ui::SystemMonitor* system_monitor = ui::SystemMonitor::Get();
+  base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
   if (system_monitor)
     system_monitor->RemoveObserver(this);
   BrowserList::RemoveObserver(this);
diff --git a/chrome/browser/profiles/profile_manager.h b/chrome/browser/profiles/profile_manager.h
index 3c2c8e7..de656d6 100644
--- a/chrome/browser/profiles/profile_manager.h
+++ b/chrome/browser/profiles/profile_manager.h
@@ -17,12 +17,12 @@
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/threading/non_thread_safe.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
-#include "ui/base/system_monitor/system_monitor.h"
 
 class FilePath;
 class NewProfileLauncher;
@@ -39,7 +39,7 @@ class ProfileManagerObserver {
 };
 
 class ProfileManager : public base::NonThreadSafe,
-                       public ui::SystemMonitor::PowerObserver,
+                       public base::SystemMonitor::PowerObserver,
                        public BrowserList::Observer,
                        public NotificationObserver,
                        public Profile::Delegate {
diff --git a/chrome/browser/profiles/profile_manager_unittest.cc b/chrome/browser/profiles/profile_manager_unittest.cc
index 541fd59..54bcbc9 100644
--- a/chrome/browser/profiles/profile_manager_unittest.cc
+++ b/chrome/browser/profiles/profile_manager_unittest.cc
@@ -8,6 +8,7 @@
 #include "base/memory/scoped_temp_dir.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/values.h"
 #include "chrome/browser/prefs/browser_prefs.h"
 #include "chrome/browser/profiles/profile.h"
@@ -22,7 +23,6 @@
 #include "content/common/notification_service.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "ui/base/system_monitor/system_monitor.h"
 
 namespace {
 // This global variable is used to check that value returned to different
@@ -61,7 +61,7 @@ class ProfileManagerTest : public TestingBrowserProcessTest {
   BrowserThread ui_thread_;
   BrowserThread file_thread_;
 
-  ui::SystemMonitor system_monitor_dummy_;
+  base::SystemMonitor system_monitor_dummy_;
 
   // Also will test profile deletion.
   scoped_ptr<ProfileManager> profile_manager_;
diff --git a/chrome/browser/tabs/tab_strip_model_unittest.cc b/chrome/browser/tabs/tab_strip_model_unittest.cc
index fc1c941..3077f8c 100644
--- a/chrome/browser/tabs/tab_strip_model_unittest.cc
+++ b/chrome/browser/tabs/tab_strip_model_unittest.cc
@@ -13,6 +13,7 @@
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/extensions/extension_tab_helper.h"
@@ -37,7 +38,6 @@
 #include "content/common/notification_source.h"
 #include "content/common/property_bag.h"
 #include "testing/gtest/include/gtest/gtest.h"
-#include "ui/base/system_monitor/system_monitor.h"
 
 using testing::_;
 
@@ -262,8 +262,8 @@ class TabStripModelTest : public RenderViewHostTestHarness {
   std::wstring profile_path_;
   std::map<TabContents*, int> foo_;
 
-  // ProfileManager requires a ui::SystemMonitor.
-  ui::SystemMonitor system_monitor;
+  // ProfileManager requires a base::SystemMonitor.
+  base::SystemMonitor system_monitor;
 
   ProfileManager pm_;
 };
diff --git a/chrome/nacl/nacl_main.cc b/chrome/nacl/nacl_main.cc
index 51c57b8..f2e0cbf 100644
--- a/chrome/nacl/nacl_main.cc
+++ b/chrome/nacl/nacl_main.cc
@@ -11,6 +11,7 @@
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
+#include "base/system_monitor/system_monitor.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/logging_chrome.h"
@@ -21,7 +22,6 @@
 #include "content/common/hi_res_timer_manager.h"
 #include "content/common/main_function_params.h"
 #include "content/common/result_codes.h"
-#include "ui/base/system_monitor/system_monitor.h"
 
 #if defined(OS_WIN)
 #include "chrome/nacl/broker_thread.h"
@@ -37,7 +37,7 @@ int NaClBrokerMain(const MainFunctionParams& parameters) {
   MessageLoopForIO main_message_loop;
   base::PlatformThread::SetName("CrNaClBrokerMain");
 
-  ui::SystemMonitor system_monitor;
+  base::SystemMonitor system_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
   const CommandLine& parsed_command_line = parameters.command_line_;
@@ -101,7 +101,7 @@ int NaClMain(const MainFunctionParams& parameters) {
   MessageLoopForIO main_message_loop;
   base::PlatformThread::SetName("CrNaClMain");
 
-  ui::SystemMonitor system_monitor;
+  base::SystemMonitor system_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
diff --git a/chrome/utility/utility_main.cc b/chrome/utility/utility_main.cc
index 9d4a63d..d4647f0 100644
--- a/chrome/utility/utility_main.cc
+++ b/chrome/utility/utility_main.cc
@@ -4,6 +4,7 @@
 
 #include "base/command_line.h"
 #include "base/message_loop.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/threading/platform_thread.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension_l10n_util.h"
@@ -11,7 +12,6 @@
 #include "content/common/child_process.h"
 #include "content/common/hi_res_timer_manager.h"
 #include "content/common/main_function_params.h"
-#include "ui/base/system_monitor/system_monitor.h"
 #include "ui/base/ui_base_switches.h"
 
 #if defined(OS_WIN)
@@ -28,7 +28,7 @@ int UtilityMain(const MainFunctionParams& parameters) {
   MessageLoop main_message_loop;
   base::PlatformThread::SetName("CrUtilityMain");
 
-  ui::SystemMonitor system_monitor;
+  base::SystemMonitor system_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
   ChildProcess utility_process;
diff --git a/chrome_frame/test/net/fake_external_tab.cc b/chrome_frame/test/net/fake_external_tab.cc
index 08127b9..20e5dea 100644
--- a/chrome_frame/test/net/fake_external_tab.cc
+++ b/chrome_frame/test/net/fake_external_tab.cc
@@ -19,6 +19,7 @@
 #include "base/path_service.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/test/test_timeouts.h"
 #include "base/threading/platform_thread.h"
 #include "base/win/scoped_comptr.h"
@@ -208,7 +209,7 @@ FakeExternalTab::~FakeExternalTab() {
 
 void FakeExternalTab::Initialize() {
   DCHECK(g_browser_process == NULL);
-  ui::SystemMonitor system_monitor;
+  base::SystemMonitor system_monitor;
 
   icu_util::Initialize();
 
diff --git a/content/common/hi_res_timer_manager.h b/content/common/hi_res_timer_manager.h
index af522cd..5c3ae38 100644
--- a/content/common/hi_res_timer_manager.h
+++ b/content/common/hi_res_timer_manager.h
@@ -6,16 +6,16 @@
 #define CONTENT_COMMON_HI_RES_TIMER_MANAGER_H_
 #pragma once
 
-#include "ui/base/system_monitor/system_monitor.h"
+#include "base/system_monitor/system_monitor.h"
 
 // Ensures that the Windows high resolution timer is only used
 // when not running on battery power.
-class HighResolutionTimerManager : public ui::SystemMonitor::PowerObserver {
+class HighResolutionTimerManager : public base::SystemMonitor::PowerObserver {
  public:
   HighResolutionTimerManager();
   virtual ~HighResolutionTimerManager();
 
-  // ui::SystemMonitor::PowerObserver:
+  // base::SystemMonitor::PowerObserver:
   virtual void OnPowerStateChange(bool on_battery_power);
 
   // Returns true if the hi resolution clock could be used right now.
diff --git a/content/common/hi_res_timer_manager_unittest.cc b/content/common/hi_res_timer_manager_unittest.cc
index 51ec295..64cd9fa 100644
--- a/content/common/hi_res_timer_manager_unittest.cc
+++ b/content/common/hi_res_timer_manager_unittest.cc
@@ -1,18 +1,18 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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 "testing/gtest/include/gtest/gtest.h"
+#include "content/common/hi_res_timer_manager.h"
 
 #include "base/memory/scoped_ptr.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/time.h"
-#include "content/common/hi_res_timer_manager.h"
-#include "ui/base/system_monitor/system_monitor.h"
+#include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(OS_WIN)
 TEST(HiResTimerManagerTest, FLAKY_ToggleOnOff) {
   MessageLoop loop;
-  scoped_ptr<ui::SystemMonitor> system_monitor(new ui::SystemMonitor());
+  scoped_ptr<base::SystemMonitor> system_monitor(new base::SystemMonitor());
   HighResolutionTimerManager manager;
 
   // At this point, we don't know if the high resolution timers are on or off,
diff --git a/content/common/hi_res_timer_manager_win.cc b/content/common/hi_res_timer_manager_win.cc
index d41c4bd..45f22ba 100644
--- a/content/common/hi_res_timer_manager_win.cc
+++ b/content/common/hi_res_timer_manager_win.cc
@@ -8,13 +8,13 @@
 
 HighResolutionTimerManager::HighResolutionTimerManager()
     : hi_res_clock_available_(false) {
-  ui::SystemMonitor* system_monitor = ui::SystemMonitor::Get();
+  base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
   system_monitor->AddObserver(this);
   UseHiResClock(!system_monitor->BatteryPower());
 }
 
 HighResolutionTimerManager::~HighResolutionTimerManager() {
-  ui::SystemMonitor::Get()->RemoveObserver(this);
+  base::SystemMonitor::Get()->RemoveObserver(this);
   UseHiResClock(false);
 }
 
diff --git a/content/plugin/plugin_main.cc b/content/plugin/plugin_main.cc
index fef3e95..2dea5e6 100644
--- a/content/plugin/plugin_main.cc
+++ b/content/plugin/plugin_main.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -12,13 +12,13 @@
 #include "base/command_line.h"
 #include "base/message_loop.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/common/content_switches.h"
 #include "content/common/hi_res_timer_manager.h"
 #include "content/common/main_function_params.h"
 #include "content/plugin/plugin_thread.h"
-#include "ui/base/system_monitor/system_monitor.h"
 
 #if defined(OS_WIN)
 #include "content/common/injection_test_dll.h"
@@ -86,7 +86,7 @@ int PluginMain(const MainFunctionParams& parameters) {
   MessageLoop main_message_loop(MessageLoop::TYPE_UI);
   base::PlatformThread::SetName("CrPluginMain");
 
-  ui::SystemMonitor system_monitor;
+  base::SystemMonitor system_monitor;
   HighResolutionTimerManager high_resolution_timer_manager;
 
   const CommandLine& parsed_command_line = parameters.command_line_;
diff --git a/content/renderer/renderer_main.cc b/content/renderer/renderer_main.cc
index 36c73ba..2551e14 100644
--- a/content/renderer/renderer_main.cc
+++ b/content/renderer/renderer_main.cc
@@ -19,6 +19,7 @@
 #include "base/path_service.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/content_counters.h"
@@ -29,7 +30,6 @@
 #include "content/renderer/render_process_impl.h"
 #include "content/renderer/render_thread.h"
 #include "content/renderer/renderer_main_platform_delegate.h"
-#include "ui/base/system_monitor/system_monitor.h"
 #include "ui/base/ui_base_switches.h"
 
 #if defined(OS_MACOSX)
@@ -176,7 +176,7 @@ int RendererMain(const MainFunctionParams& parameters) {
 
   base::PlatformThread::SetName("CrRendererMain");
 
-  ui::SystemMonitor system_monitor;
+  base::SystemMonitor system_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
   platform.PlatformInitialize();
diff --git a/content/worker/worker_main.cc b/content/worker/worker_main.cc
index 6ec0263..88acc21 100644
--- a/content/worker/worker_main.cc
+++ b/content/worker/worker_main.cc
@@ -6,12 +6,12 @@
 #include "base/command_line.h"
 #include "base/message_loop.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/common/hi_res_timer_manager.h"
 #include "content/common/main_function_params.h"
 #include "content/worker/worker_thread.h"
-#include "ui/base/system_monitor/system_monitor.h"
 
 #if defined(OS_WIN)
 #include "content/common/sandbox_init_wrapper.h"
@@ -24,7 +24,7 @@ int WorkerMain(const MainFunctionParams& parameters) {
   MessageLoop main_message_loop;
   base::PlatformThread::SetName("CrWorkerMain");
 
-  ui::SystemMonitor system_monitor;
+  base::SystemMonitor system_monitor;
   HighResolutionTimerManager hi_res_timer_manager;
 
   ChildProcess worker_process;
diff --git a/ui/views/widget/native_widget_win.cc b/ui/views/widget/native_widget_win.cc
index 8a5ad92..4247547 100644
--- a/ui/views/widget/native_widget_win.cc
+++ b/ui/views/widget/native_widget_win.cc
@@ -5,7 +5,7 @@
 #include "ui/views/widget/native_widget_win.h"
 
 #include "base/memory/scoped_ptr.h"
-#include "ui/base/system_monitor/system_monitor.h"
+#include "base/system_monitor/system_monitor.h"
 #include "ui/base/view_prop.h"
 #include "ui/base/win/hwnd_util.h"
 #include "ui/gfx/canvas_skia.h"
diff --git a/views/widget/widget_win.cc b/views/widget/widget_win.cc
index 460fa5d..65e2e77 100644
--- a/views/widget/widget_win.cc
+++ b/views/widget/widget_win.cc
@@ -7,6 +7,7 @@
 #include <dwmapi.h>
 
 #include "base/string_util.h"
+#include "base/system_monitor/system_monitor.h"
 #include "base/win/windows_version.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/dragdrop/drag_source.h"
@@ -14,7 +15,6 @@
 #include "ui/base/dragdrop/os_exchange_data_provider_win.h"
 #include "ui/base/keycodes/keyboard_code_conversion_win.h"
 #include "ui/base/l10n/l10n_util_win.h"
-#include "ui/base/system_monitor/system_monitor.h"
 #include "ui/base/theme_provider.h"
 #include "ui/base/view_prop.h"
 #include "ui/base/win/hwnd_util.h"
@@ -859,7 +859,7 @@ void WidgetWin::OnPaint(HDC dc) {
 }
 
 LRESULT WidgetWin::OnPowerBroadcast(DWORD power_event, DWORD data) {
-  ui::SystemMonitor* monitor = ui::SystemMonitor::Get();
+  base::SystemMonitor* monitor = base::SystemMonitor::Get();
   if (monitor)
     monitor->ProcessWmPowerBroadcastMessage(power_event);
   SetMsgHandled(FALSE);