add device type as an argument in OnDevicesChanged.

This allows DevicesChangedObserver to listen to desired events, instead of being woken up by change of uninterested devices.

BUG=137799
Review URL: https://chromiumcodereview.appspot.com/10836004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149103 0039d316-1c4b-4281-b951-d872f2087c98

base/system_monitor/system_monitor.cc

@@ -83,8 +83,8 @@ void SystemMonitor::ProcessPowerMessage(PowerEvent event_id) {
   }
 }
 
-void SystemMonitor::ProcessDevicesChanged() {
-  NotifyDevicesChanged();
+void SystemMonitor::ProcessDevicesChanged(DeviceType device_type) {
+  NotifyDevicesChanged(device_type);
 }
 
 void SystemMonitor::ProcessMediaDeviceAttached(
@@ -136,10 +136,10 @@ void SystemMonitor::RemoveDevicesChangedObserver(DevicesChangedObserver* obs) {
   devices_changed_observer_list_->RemoveObserver(obs);
 }
 
-void SystemMonitor::NotifyDevicesChanged() {
-  DVLOG(1) << "DevicesChanged";
+void SystemMonitor::NotifyDevicesChanged(DeviceType device_type) {
+  DVLOG(1) << "DevicesChanged with device type " << device_type;
   devices_changed_observer_list_->Notify(
-    &DevicesChangedObserver::OnDevicesChanged);
+      &DevicesChangedObserver::OnDevicesChanged, device_type);
 }
 
 void SystemMonitor::NotifyMediaDeviceAttached(

base/system_monitor/system_monitor.h

@@ -51,6 +51,13 @@ class BASE_EXPORT SystemMonitor {
     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.
+    DEVTYPE_VIDEO_CAPTURE,  // Video capture device, e.g., webcam.
+    DEVTYPE_UNKNOWN,  // Other devices.
+  };
+
   // Type of location data to identify a currently attached media device.
   enum MediaDeviceType {
     TYPE_PATH,  // FilePath::StringType, e.g. a mount point.
@@ -140,7 +147,7 @@ class BASE_EXPORT SystemMonitor {
    public:
     // Notification that the devices connected to the system have changed.
     // This is only implemented on Windows currently.
-    virtual void OnDevicesChanged() {}
+    virtual void OnDevicesChanged(DeviceType device_type) {}
 
     // When a media device is attached or detached, one of these two events
     // is triggered.
@@ -178,7 +185,7 @@ class BASE_EXPORT SystemMonitor {
   void ProcessPowerMessage(PowerEvent event_id);
 
   // Cross-platform handling of a device change event.
-  void ProcessDevicesChanged();
+  void ProcessDevicesChanged(DeviceType device_type);
   void ProcessMediaDeviceAttached(const std::string& id,
                                   const string16& name,
                                   MediaDeviceType type,
@@ -204,7 +211,7 @@ class BASE_EXPORT SystemMonitor {
   void BatteryCheck();
 
   // Functions to trigger notifications.
-  void NotifyDevicesChanged();
+  void NotifyDevicesChanged(DeviceType device_type);
   void NotifyMediaDeviceAttached(const std::string& id,
                                  const string16& name,
                                  MediaDeviceType type,

base/system_monitor/system_monitor_unittest.cc

@@ -118,7 +118,8 @@ TEST_F(SystemMonitorTest, DeviceChangeNotifications) {
   for (int index = 0; index < kObservers; ++index) {
     system_monitor_->AddDevicesChangedObserver(&observers[index]);
 
-    EXPECT_CALL(observers[index], OnDevicesChanged())
+    EXPECT_CALL(observers[index],
+                OnDevicesChanged(base::SystemMonitor::DEVTYPE_UNKNOWN))
         .Times(3)
         .InSequence(mock_sequencer[index]);
     EXPECT_CALL(observers[index],
@@ -133,11 +134,11 @@ TEST_F(SystemMonitorTest, DeviceChangeNotifications) {
         .InSequence(mock_sequencer[index]);
   }
 
-  system_monitor_->ProcessDevicesChanged();
+  system_monitor_->ProcessDevicesChanged(base::SystemMonitor::DEVTYPE_UNKNOWN);
   message_loop_.RunAllPending();
 
-  system_monitor_->ProcessDevicesChanged();
-  system_monitor_->ProcessDevicesChanged();
+  system_monitor_->ProcessDevicesChanged(base::SystemMonitor::DEVTYPE_UNKNOWN);
+  system_monitor_->ProcessDevicesChanged(base::SystemMonitor::DEVTYPE_UNKNOWN);
   message_loop_.RunAllPending();
 
   system_monitor_->ProcessMediaDeviceAttached(

base/test/mock_devices_changed_observer.h

@@ -18,7 +18,8 @@ class MockDevicesChangedObserver
   MockDevicesChangedObserver();
   ~MockDevicesChangedObserver();
 
-  MOCK_METHOD0(OnDevicesChanged, void());
+  MOCK_METHOD1(OnDevicesChanged,
+               void(base::SystemMonitor::DeviceType device_type));
   MOCK_METHOD4(OnMediaDeviceAttached,
                void(const std::string& id,
                     const string16& name,

content/browser/gamepad/gamepad_provider.cc

@@ -91,7 +91,7 @@ void GamepadProvider::Resume() {
       base::Bind(&GamepadProvider::ScheduleDoPoll, Unretained(this)));
 }
 
-void GamepadProvider::OnDevicesChanged() {
+void GamepadProvider::OnDevicesChanged(base::SystemMonitor::DeviceType type) {
   base::AutoLock lock(devices_changed_lock_);
   devices_changed_ = true;
 }

content/browser/gamepad/gamepad_provider.h

@@ -40,7 +40,7 @@ class CONTENT_EXPORT GamepadProvider :
   void Resume();
 
   // base::SystemMonitor::DevicesChangedObserver implementation.
-  virtual void OnDevicesChanged() OVERRIDE;
+  virtual void OnDevicesChanged(base::SystemMonitor::DeviceType type) OVERRIDE;
 
  private:
 

content/browser/system_message_window_win.cc

@@ -41,7 +41,7 @@ LRESULT SystemMessageWindowWin::OnDeviceChange(UINT event_type, DWORD data) {
   base::SystemMonitor* monitor = base::SystemMonitor::Get();
   switch (event_type) {
     case DBT_DEVNODES_CHANGED:
-      monitor->ProcessDevicesChanged();
+      monitor->ProcessDevicesChanged(base::SystemMonitor::DEVTYPE_UNKNOWN);
       break;
   }
   return TRUE;

content/browser/system_message_window_win_unittest.cc

@@ -30,7 +30,7 @@ class SystemMessageWindowWinTest : public testing::Test {
 };
 
 TEST_F(SystemMessageWindowWinTest, DevicesChanged) {
-  EXPECT_CALL(observer_, OnDevicesChanged()).Times(1);
+  EXPECT_CALL(observer_, OnDevicesChanged(testing::_)).Times(1);
   window_.OnDeviceChange(DBT_DEVNODES_CHANGED, NULL);
   message_loop_.RunAllPending();
 }