Clean up old Mojo types for DevicesChangedObserver

This CL cleans up old Mojo types for DevicesChangedObserver
from VirtualDeviceEnabledDeviceFactory.

Bug: 955171
Change-Id: I3cac65b00124e0735a8656190fe9c2cbdd9c3e68
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1882266Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Oksana Zhuravlova <oksamyt@chromium.org>
Commit-Queue: Julie Kim <jkim@igalia.com>
Cr-Commit-Position: refs/heads/master@{#710119}

services/video_capture/virtual_device_enabled_device_factory.cc

@@ -239,7 +239,7 @@ void VirtualDeviceEnabledDeviceFactory::EmitDevicesChangedEvent() {
 }
 
 void VirtualDeviceEnabledDeviceFactory::OnDevicesChangedObserverDisconnected(
-    mojom::DevicesChangedObserverPtr::Proxy* observer) {
+    mojom::DevicesChangedObserver* observer) {
   for (auto iter = devices_changed_observers_.begin();
        iter != devices_changed_observers_.end(); ++iter) {
     if (iter->get() == observer) {

services/video_capture/virtual_device_enabled_device_factory.h

@@ -57,7 +57,7 @@ class VirtualDeviceEnabledDeviceFactory : public DeviceFactory {
       const std::string& device_id);
   void EmitDevicesChangedEvent();
   void OnDevicesChangedObserverDisconnected(
-      mojom::DevicesChangedObserverPtr::Proxy* observer);
+      mojom::DevicesChangedObserver* observer);
 
   std::map<std::string, VirtualDeviceEntry> virtual_devices_by_id_;
   const std::unique_ptr<DeviceFactory> device_factory_;