Move power event handling logic from ui/ layer to base/ on Windows

This fix is to create a new window for receiving and handling power broadcast message
in base/ instead of in each HWNDMessageHandler instance. It addressed the issue of layer
violation in power message handling and make base/ self-contained.

BUG=149059


Review URL: https://chromiumcodereview.appspot.com/11821050

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@185433 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 102 insertions, 32 deletions

diff --git a/base/system_monitor/system_monitor.h b/base/system_monitor/system_monitor.h
index 6620d27..10f279f 100644
--- a/base/system_monitor/system_monitor.h
+++ b/base/system_monitor/system_monitor.h
@@ -134,13 +134,6 @@ class BASE_EXPORT SystemMonitor {
   // be copied. Any significant addition to this class is blocked on
   // refactoring to improve the state of affairs. See http://crbug.com/149059
 
-#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);
 
@@ -148,6 +141,29 @@ class BASE_EXPORT SystemMonitor {
   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();
@@ -183,6 +199,10 @@ class BASE_EXPORT SystemMonitor {
   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_win.cc b/base/system_monitor/system_monitor_win.cc
index 69ab85e..562b69b 100644
--- a/base/system_monitor/system_monitor_win.cc
+++ b/base/system_monitor/system_monitor_win.cc
@@ -4,23 +4,69 @@
 
 #include "base/system_monitor/system_monitor.h"
 
+#include "base/win/wrapped_window_proc.h"
+
 namespace base {
 
-void SystemMonitor::ProcessWmPowerBroadcastMessage(int event_id) {
-  PowerEvent power_event;
+namespace {
+
+const wchar_t kWindowClassName[] = L"Base_PowerMessageWindow";
+
+}  // namespace
+
+// 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)) {
+    DLOG_GETLASTERROR(ERROR) << "GetSystemPowerStatus failed";
+    return false;
+  }
+  return (status.ACLineStatus == 0);
+}
+
+SystemMonitor::PowerMessageWindow::PowerMessageWindow()
+    : instance_(NULL), message_hwnd_(NULL) {
+  WNDCLASSEX window_class;
+  base::win::InitializeWindowClass(
+      kWindowClassName,
+      &base::win::WrappedWindowProc<
+          SystemMonitor::PowerMessageWindow::WndProcThunk>,
+      0, 0, 0, NULL, NULL, NULL, NULL, NULL,
+      &window_class);
+  instance_ = window_class.hInstance;
+  ATOM clazz = RegisterClassEx(&window_class);
+  DCHECK(clazz);
+
+  message_hwnd_ = CreateWindowEx(WS_EX_NOACTIVATE, kWindowClassName,
+      NULL, WS_POPUP, 0, 0, 0, 0, NULL, NULL, instance_, NULL);
+  SetWindowLongPtr(message_hwnd_, GWLP_USERDATA,
+                   reinterpret_cast<LONG_PTR>(this));
+}
+
+SystemMonitor::PowerMessageWindow::~PowerMessageWindow() {
+  if (message_hwnd_) {
+    DestroyWindow(message_hwnd_);
+    UnregisterClass(kWindowClassName, instance_);
+  }
+}
+
+void SystemMonitor::PowerMessageWindow::ProcessWmPowerBroadcastMessage(
+    int event_id) {
+  SystemMonitor::PowerEvent power_event;
   switch (event_id) {
     case PBT_APMPOWERSTATUSCHANGE:  // The power status changed.
-      power_event = POWER_STATE_EVENT;
+      power_event = SystemMonitor::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;
+      power_event = SystemMonitor::RESUME_EVENT;
       break;
     case PBT_APMSUSPEND:  // System has been suspended.
-      power_event = SUSPEND_EVENT;
+      power_event = SystemMonitor::SUSPEND_EVENT;
       break;
     default:
       return;
@@ -33,18 +79,33 @@ void SystemMonitor::ProcessWmPowerBroadcastMessage(int event_id) {
     // PBT_APMRESUMECRITICAL - removed in Vista.
     // PBT_POWERSETTINGCHANGE - user changed the power settings.
   }
-  ProcessPowerMessage(power_event);
+
+  SystemMonitor::Get()->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)) {
-    DLOG_GETLASTERROR(ERROR) << "GetSystemPowerStatus failed";
-    return false;
+LRESULT CALLBACK SystemMonitor::PowerMessageWindow::WndProc(
+    HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
+  switch (message) {
+    case WM_POWERBROADCAST: {
+      DWORD power_event = static_cast<DWORD>(message);
+      ProcessWmPowerBroadcastMessage(power_event);
+      return TRUE;
+    }
+    default:
+      break;
   }
-  return (status.ACLineStatus == 0);
+  return ::DefWindowProc(hwnd, message, wparam, lparam);
+}
+
+// static
+LRESULT CALLBACK SystemMonitor::PowerMessageWindow::WndProcThunk(
+    HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) {
+  SystemMonitor::PowerMessageWindow* message_hwnd =
+      reinterpret_cast<SystemMonitor::PowerMessageWindow*>(
+          GetWindowLongPtr(hwnd, GWLP_USERDATA));
+  if (message_hwnd)
+    return message_hwnd->WndProc(hwnd, message, wparam, lparam);
+  return ::DefWindowProc(hwnd, message, wparam, lparam);
 }
 
 }  // namespace base
diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index d1c8534..8c7fdbb 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -9,7 +9,6 @@
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
-#include "base/system_monitor/system_monitor.h"
 #include "base/win/windows_version.h"
 #include "ui/base/events/event.h"
 #include "ui/base/events/event_utils.h"
@@ -1888,14 +1887,6 @@ void HWNDMessageHandler::OnPaint(HDC dc) {
   }
 }
 
-LRESULT HWNDMessageHandler::OnPowerBroadcast(DWORD power_event, DWORD data) {
-  base::SystemMonitor* monitor = base::SystemMonitor::Get();
-  if (monitor)
-    monitor->ProcessWmPowerBroadcastMessage(power_event);
-  SetMsgHandled(FALSE);
-  return 0;
-}
-
 LRESULT HWNDMessageHandler::OnReflectedMessage(UINT message,
                                                WPARAM w_param,
                                                LPARAM l_param) {
diff --git a/ui/views/win/hwnd_message_handler.h b/ui/views/win/hwnd_message_handler.h
index f69979f..3654b93 100644
--- a/ui/views/win/hwnd_message_handler.h
+++ b/ui/views/win/hwnd_message_handler.h
@@ -296,7 +296,6 @@ class VIEWS_EXPORT HWNDMessageHandler : public ui::WindowImpl,
     MSG_WM_NCPAINT(OnNCPaint)
     MSG_WM_NOTIFY(OnNotify)
     MSG_WM_PAINT(OnPaint)
-    MSG_WM_POWERBROADCAST(OnPowerBroadcast)
     MSG_WM_SETFOCUS(OnSetFocus)
     MSG_WM_SETICON(OnSetIcon)
     MSG_WM_SETTEXT(OnSetText)
@@ -346,7 +345,6 @@ class VIEWS_EXPORT HWNDMessageHandler : public ui::WindowImpl,
   LRESULT OnNCUAHDrawFrame(UINT message, WPARAM w_param, LPARAM l_param);
   LRESULT OnNotify(int w_param, NMHDR* l_param);
   void OnPaint(HDC dc);
-  LRESULT OnPowerBroadcast(DWORD power_event, DWORD data);
   LRESULT OnReflectedMessage(UINT message, WPARAM w_param, LPARAM l_param);
   LRESULT OnSetCursor(UINT message, WPARAM w_param, LPARAM l_param);
   void OnSetFocus(HWND last_focused_window);