Send WM_DEVICECHANGE message through SystemMonitor

WM_DEVICECHANGE is sent when there's been a change to devices or the computer;
specifically when a USB device is connected or disconnected. This is intended
for use in support of Gamepads for more performant polling and
connect/disconnect testing. Currently only on Windows, though seems reasonable
to add for other platforms in the future.

BUG=79050


Review URL: http://codereview.chromium.org/8523021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@109960 0039d316-1c4b-4281-b951-d872f2087c98

base/system_monitor/system_monitor.cc

@@ -19,7 +19,9 @@ static int kDelayedBatteryCheckMs = 10 * 1000;
 #endif  // defined(ENABLE_BATTERY_MONITORING)
 
 SystemMonitor::SystemMonitor()
-    : observer_list_(new ObserverListThreadSafe<PowerObserver>()),
+    : power_observer_list_(new ObserverListThreadSafe<PowerObserver>()),
+      devices_changed_observer_list_(
+          new ObserverListThreadSafe<DevicesChangedObserver>()),
       battery_in_use_(false),
       suspended_(false) {
   DCHECK(!g_system_monitor);
@@ -77,28 +79,47 @@ void SystemMonitor::ProcessPowerMessage(PowerEvent event_id) {
   }
 }
 
-void SystemMonitor::AddObserver(PowerObserver* obs) {
-  observer_list_->AddObserver(obs);
+void SystemMonitor::ProcessDevicesChanged() {
+  NotifyDevicesChanged();
 }
 
-void SystemMonitor::RemoveObserver(PowerObserver* obs) {
-  observer_list_->RemoveObserver(obs);
+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);
+}
+
+void SystemMonitor::RemoveDevicesChangedObserver(DevicesChangedObserver* obs) {
+  devices_changed_observer_list_->RemoveObserver(obs);
+}
+
+void SystemMonitor::NotifyDevicesChanged() {
+  DVLOG(1) << "DevicesChanged";
+  devices_changed_observer_list_->Notify(
+    &DevicesChangedObserver::OnDevicesChanged);
 }
 
 void SystemMonitor::NotifyPowerStateChange() {
   DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
            << " battery";
-  observer_list_->Notify(&PowerObserver::OnPowerStateChange, BatteryPower());
+  power_observer_list_->Notify(&PowerObserver::OnPowerStateChange,
+                               BatteryPower());
 }
 
 void SystemMonitor::NotifySuspend() {
   DVLOG(1) << "Power Suspending";
-  observer_list_->Notify(&PowerObserver::OnSuspend);
+  power_observer_list_->Notify(&PowerObserver::OnSuspend);
 }
 
 void SystemMonitor::NotifyResume() {
   DVLOG(1) << "Power Resuming";
-  observer_list_->Notify(&PowerObserver::OnResume);
+  power_observer_list_->Notify(&PowerObserver::OnResume);
 }
 
 void SystemMonitor::BatteryCheck() {

base/system_monitor/system_monitor.h

@@ -90,15 +90,26 @@ class BASE_EXPORT SystemMonitor {
     virtual ~PowerObserver() {}
   };
 
+  class BASE_EXPORT DevicesChangedObserver {
+   public:
+    // Notification that the devices connected to the system have changed.
+    virtual void OnDevicesChanged() {}
+
+   protected:
+    virtual ~DevicesChangedObserver() {}
+  };
+
   // Add a new observer.
   // Can be called from any thread.
   // Must not be called from within a notification callback.
-  void AddObserver(PowerObserver* obs);
+  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 RemoveObserver(PowerObserver* obs);
+  void RemovePowerObserver(PowerObserver* obs);
+  void RemoveDevicesChangedObserver(DevicesChangedObserver* obs);
 
 #if defined(OS_WIN)
   // Windows-specific handling of a WM_POWERBROADCAST message.
@@ -110,6 +121,9 @@ class BASE_EXPORT SystemMonitor {
   // Cross-platform handling of a power event.
   void ProcessPowerMessage(PowerEvent event_id);
 
+  // Cross-platform handling of a device change event.
+  void ProcessDevicesChanged();
+
  private:
 #if defined(OS_MACOSX)
   void PlatformInit();
@@ -126,11 +140,14 @@ class BASE_EXPORT SystemMonitor {
   void BatteryCheck();
 
   // Functions to trigger notifications.
+  void NotifyDevicesChanged();
   void NotifyPowerStateChange();
   void NotifySuspend();
   void NotifyResume();
 
-  scoped_refptr<ObserverListThreadSafe<PowerObserver> > observer_list_;
+  scoped_refptr<ObserverListThreadSafe<PowerObserver> > power_observer_list_;
+  scoped_refptr<ObserverListThreadSafe<DevicesChangedObserver> >
+      devices_changed_observer_list_;
   bool battery_in_use_;
   bool suspended_;
 

base/system_monitor/system_monitor_unittest.cc

@@ -55,7 +55,7 @@ TEST(SystemMonitor, PowerNotifications) {
   SystemMonitor system_monitor;
   PowerTest test[kObservers];
   for (int index = 0; index < kObservers; ++index)
-    system_monitor.AddObserver(&test[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.
@@ -90,4 +90,49 @@ TEST(SystemMonitor, PowerNotifications) {
   EXPECT_EQ(test[0].resumes(), 1);
 }
 
+class DevicesChangedTest : public SystemMonitor::DevicesChangedObserver {
+ public:
+  DevicesChangedTest()
+      : changes_(0) {
+  }
+
+  // DevicesChangedObserver callbacks.
+  virtual void OnDevicesChanged() OVERRIDE {
+    changes_++;
+  }
+
+  // Test status counts.
+  int changes() const { return changes_; }
+
+ private:
+  int changes_;  // Count of OnDevicesChanged notifications.
+
+  DISALLOW_COPY_AND_ASSIGN(DevicesChangedTest);
+};
+
+TEST(SystemMonitor, DeviceChangeNotifications) {
+  const int kObservers = 5;
+
+  // Initialize a message loop for this to run on.
+  MessageLoop loop;
+
+#if defined(OS_MACOSX)
+  SystemMonitor::AllocateSystemIOPorts();
+#endif
+
+  SystemMonitor system_monitor;
+  DevicesChangedTest test[kObservers];
+  for (int index = 0; index < kObservers; ++index)
+    system_monitor.AddDevicesChangedObserver(&test[index]);
+
+  system_monitor.ProcessDevicesChanged();
+  loop.RunAllPending();
+  EXPECT_EQ(1, test[0].changes());
+
+  system_monitor.ProcessDevicesChanged();
+  system_monitor.ProcessDevicesChanged();
+  loop.RunAllPending();
+  EXPECT_EQ(3, test[0].changes());
+}
+
 }  // namespace base

content/browser/browser_main_loop.cc

@@ -33,6 +33,7 @@
 #include <ole2.h>
 #include <shellapi.h>
 
+#include "content/browser/system_message_window_win.h"
 #include "ui/base/l10n/l10n_util_win.h"
 #include "net/base/winsock_init.h"
 #endif
@@ -256,6 +257,10 @@ void BrowserMainLoop::MainMessageLoopStart() {
 
   network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
 
+#if defined(OS_WIN)
+  system_message_window_.reset(new SystemMessageWindowWin);
+#endif
+
   for (size_t i = 0; i < parts_list_.size(); ++i)
     parts_list_[i]->PostMainMessageLoopStart();
 }

content/browser/browser_main_loop.h

@@ -14,6 +14,7 @@
 class CommandLine;
 class HighResolutionTimerManager;
 class MessageLoop;
+class SystemMessageWindowWin;
 
 namespace base {
 class SystemMonitor;
@@ -64,6 +65,9 @@ class BrowserMainLoop {
   scoped_ptr<base::SystemMonitor> system_monitor_;
   scoped_ptr<HighResolutionTimerManager> hi_res_timer_manager_;
   scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
+#if defined(OS_WIN)
+  scoped_ptr<SystemMessageWindowWin> system_message_window_;
+#endif
   scoped_ptr<BrowserThreadImpl> main_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);

content/browser/system_message_window_win.cc

+// 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 "content/browser/system_message_window_win.h"
+
+#include <windows.h>
+#include <dbt.h>
+
+#include "base/system_monitor/system_monitor.h"
+#include "base/win/wrapped_window_proc.h"
+
+static const wchar_t* const WindowClassName = L"Chrome_SystemMessageWindow";
+
+SystemMessageWindowWin::SystemMessageWindowWin() {
+  HINSTANCE hinst = GetModuleHandle(NULL);
+
+  WNDCLASSEX wc = {0};
+  wc.cbSize = sizeof(wc);
+  wc.lpfnWndProc =
+      base::win::WrappedWindowProc<&SystemMessageWindowWin::WndProcThunk>;
+  wc.hInstance = hinst;
+  wc.lpszClassName = WindowClassName;
+  ATOM clazz = RegisterClassEx(&wc);
+  DCHECK(clazz);
+
+  window_ = CreateWindow(WindowClassName,
+                         0, 0, 0, 0, 0, 0, 0, 0, hinst, 0);
+  SetWindowLongPtr(window_, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(this));
+}
+
+SystemMessageWindowWin::~SystemMessageWindowWin() {
+  if (window_) {
+    DestroyWindow(window_);
+    UnregisterClass(WindowClassName, GetModuleHandle(NULL));
+  }
+}
+
+LRESULT SystemMessageWindowWin::OnDeviceChange(UINT event_type, DWORD data) {
+  base::SystemMonitor* monitor = base::SystemMonitor::Get();
+  if (monitor && event_type == DBT_DEVNODES_CHANGED)
+    monitor->ProcessDevicesChanged();
+  return TRUE;
+}
+
+LRESULT CALLBACK SystemMessageWindowWin::WndProc(HWND hwnd, UINT message,
+                                                 WPARAM wparam, LPARAM lparam) {
+  switch (message) {
+    case WM_DEVICECHANGE:
+      return OnDeviceChange(static_cast<UINT>(wparam),
+                            static_cast<DWORD>(lparam));
+    default:
+      break;
+  }
+
+  return ::DefWindowProc(hwnd, message, wparam, lparam);
+}

content/browser/system_message_window_win.h

+// 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 CONTENT_BROWSER_SYSTEM_MESSAGE_WINDOW_WIN_H_
+#define CONTENT_BROWSER_SYSTEM_MESSAGE_WINDOW_WIN_H_
+#pragma once
+
+#include "build/build_config.h"
+
+#include <windows.h>
+
+#include "base/basictypes.h"
+#include "content/common/content_export.h"
+
+class CONTENT_EXPORT SystemMessageWindowWin {
+ public:
+  SystemMessageWindowWin();
+  virtual ~SystemMessageWindowWin();
+
+  virtual LRESULT OnDeviceChange(UINT event_type, DWORD data);
+
+ private:
+  LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
+                           WPARAM wparam, LPARAM lparam);
+
+  static LRESULT CALLBACK WndProcThunk(HWND hwnd,
+                                       UINT message,
+                                       WPARAM wparam,
+                                       LPARAM lparam) {
+    SystemMessageWindowWin* msg_wnd = reinterpret_cast<SystemMessageWindowWin*>(
+        GetWindowLongPtr(hwnd, GWLP_USERDATA));
+    if (msg_wnd)
+      return msg_wnd->WndProc(hwnd, message, wparam, lparam);
+    return ::DefWindowProc(hwnd, message, wparam, lparam);
+  }
+
+  HWND window_;
+
+  DISALLOW_COPY_AND_ASSIGN(SystemMessageWindowWin);
+};
+
+#endif  // CONTENT_BROWSER_SYSTEM_MESSAGE_WINDOW_WIN_H_

content/common/hi_res_timer_manager_win.cc

@@ -9,12 +9,12 @@
 HighResolutionTimerManager::HighResolutionTimerManager()
     : hi_res_clock_available_(false) {
   base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
-  system_monitor->AddObserver(this);
+  system_monitor->AddPowerObserver(this);
   UseHiResClock(!system_monitor->BatteryPower());
 }
 
 HighResolutionTimerManager::~HighResolutionTimerManager() {
-  base::SystemMonitor::Get()->RemoveObserver(this);
+  base::SystemMonitor::Get()->RemovePowerObserver(this);
   UseHiResClock(false);
 }
 

content/content_browser.gypi

@@ -511,6 +511,8 @@
     'browser/ssl/ssl_policy_backend.h',
     'browser/ssl/ssl_request_info.cc',
     'browser/ssl/ssl_request_info.h',
+    'browser/system_message_window_win.cc',
+    'browser/system_message_window_win.h',
     'browser/tab_contents/drag_utils_gtk.cc',
     'browser/tab_contents/drag_utils_gtk.h',
     'browser/tab_contents/interstitial_page.cc',

net/url_request/url_request_job.cc

@@ -34,7 +34,7 @@ URLRequestJob::URLRequestJob(URLRequest* request)
       ALLOW_THIS_IN_INITIALIZER_LIST(method_factory_(this)) {
   base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
   if (system_monitor)
-    base::SystemMonitor::Get()->AddObserver(this);
+    base::SystemMonitor::Get()->AddPowerObserver(this);
 }
 
 void URLRequestJob::SetUpload(UploadData* upload) {
@@ -219,7 +219,7 @@ void URLRequestJob::NotifyURLRequestDestroyed() {
 URLRequestJob::~URLRequestJob() {
   base::SystemMonitor* system_monitor = base::SystemMonitor::Get();
   if (system_monitor)
-    base::SystemMonitor::Get()->RemoveObserver(this);
+    base::SystemMonitor::Get()->RemovePowerObserver(this);
 }
 
 void URLRequestJob::NotifyCertificateRequested(