Remove HID devices not found during enumeration on Windows.

Windows doesn't give us fine grained notifications for device add
and remove so we must do a complete enumeration every time. This
patch figures out which devices are no longer present in the
enumeration and calls HidService::RemoveDevice.

BUG=395272
R=rockot@chromium.org

Review URL: https://codereview.chromium.org/399313008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284321 0039d316-1c4b-4281-b951-d872f2087c98

device/hid/hid_service.cc

@@ -90,6 +90,10 @@ void HidService::RemoveDevice(const HidDeviceId& device_id) {
     devices_.erase(it);
 }
 
+const HidService::DeviceMap& HidService::GetDevicesNoEnumerate() const {
+  return devices_;
+}
+
 HidService* HidService::GetInstance() {
   if (!g_hid_service_ptr.Get().get())
     g_hid_service_ptr.Get().reset(CreateInstance());

device/hid/hid_service.h

@@ -50,6 +50,7 @@ class HidService : public base::MessageLoop::DestructionObserver {
 
   void AddDevice(const HidDeviceInfo& info);
   void RemoveDevice(const HidDeviceId& device_id);
+  const DeviceMap& GetDevicesNoEnumerate() const;
 
   base::ThreadChecker thread_checker_;
 

device/hid/hid_service_win.cc

@@ -66,9 +66,9 @@ void HidServiceWin::Enumerate() {
       NULL,
       DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
 
-  if (device_info_set == INVALID_HANDLE_VALUE)
-    return;
+  std::set<std::string> connected_devices;
 
+  if (device_info_set != INVALID_HANDLE_VALUE) {
     for (int device_index = 0;
          SetupDiEnumDeviceInterfaces(device_info_set,
                                      NULL,
@@ -138,6 +138,24 @@ void HidServiceWin::Enumerate() {
         continue;
 
       PlatformAddDevice(device_interface_detail_data->DevicePath);
+      connected_devices.insert(device_interface_detail_data->DevicePath);
+    }
+  }
+
+  // Find disconnected devices.
+  const DeviceMap& devices = GetDevicesNoEnumerate();
+  std::vector<std::string> disconnected_devices;
+  for (DeviceMap::const_iterator it = devices.begin();
+       it != devices.end();
+       ++it) {
+    if (!ContainsKey(connected_devices, it->first)) {
+      disconnected_devices.push_back(it->first);
+    }
+  }
+
+  // Remove disconnected devices.
+  for (size_t i = 0; i < disconnected_devices.size(); ++i) {
+    PlatformRemoveDevice(disconnected_devices[i]);
   }
 }