arc: deliver USB detach event to container

USB detach event not delivered to Arc container

After usb_service called OnDeviceRemoved(), query usb_service for this
device will not(gurantee) return any result.

Use the scoped_refptr passed by OnDeviceRemoved directly and deliver the
detach event to ARC container.

Bug: 853353
Test: Manual
Change-Id: I74214b455a678548c3a80eebf214fdfa5beced99
Reviewed-on: https://chromium-review.googlesource.com/1103284
Commit-Queue: Long Cheng <lgcheng@google.com>
Reviewed-by: Luis Hector Chavez <lhchavez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568232}

components/arc/usb/usb_host_bridge.cc

@@ -218,8 +218,8 @@ void ArcUsbHostBridge::OnDeviceRemoved(
     return;
   }
 
-  usb_host_instance->OnDeviceRemoved(
-      device.get()->guid(), GetEventReceiverPackages(device.get()->guid()));
+  usb_host_instance->OnDeviceRemoved(device.get()->guid(),
+                                     GetEventReceiverPackages(device));
 
   if (ui_delegate_)
     ui_delegate_->DeviceRemoved(device.get()->guid());
@@ -255,10 +255,9 @@ void ArcUsbHostBridge::SetUiDelegate(ArcUsbHostUiDelegate* ui_delegate) {
 }
 
 std::vector<std::string> ArcUsbHostBridge::GetEventReceiverPackages(
-    const std::string& guid) {
-  scoped_refptr<device::UsbDevice> device = usb_service_->GetDevice(guid);
-  if (!device.get()) {
-    LOG(WARNING) << "Unknown USB device " << guid;
+    scoped_refptr<device::UsbDevice> device) {
+  if (!device) {
+    LOG(WARNING) << "Unknown USB device.";
     return std::vector<std::string>();
   }
 
@@ -266,7 +265,8 @@ std::vector<std::string> ArcUsbHostBridge::GetEventReceiverPackages(
     return std::vector<std::string>();
 
   std::unordered_set<std::string> receivers = ui_delegate_->GetEventPackageList(
-      guid, device->serial_number(), device->vendor_id(), device->product_id());
+      device->guid(), device->serial_number(), device->vendor_id(),
+      device->product_id());
 
   return std::vector<std::string>(receivers.begin(), receivers.end());
 }
@@ -283,10 +283,11 @@ void ArcUsbHostBridge::OnDeviceChecked(const std::string& guid, bool allowed) {
   mojom::UsbHostInstance* usb_host_instance = ARC_GET_INSTANCE_FOR_METHOD(
       arc_bridge_service_->usb_host(), OnDeviceAdded);
 
-  if (!usb_host_instance)
+  if (!usb_host_instance || !usb_service_)
     return;
 
-  usb_host_instance->OnDeviceAdded(guid, GetEventReceiverPackages(guid));
+  usb_host_instance->OnDeviceAdded(
+      guid, GetEventReceiverPackages(usb_service_->GetDevice(guid)));
 }
 
 void ArcUsbHostBridge::DoRequestUserAuthorization(

components/arc/usb/usb_host_bridge.h

@@ -74,7 +74,8 @@ class ArcUsbHostBridge : public KeyedService,
   void SetUiDelegate(ArcUsbHostUiDelegate* ui_delegate);
 
  private:
-  std::vector<std::string> GetEventReceiverPackages(const std::string& guid);
+  std::vector<std::string> GetEventReceiverPackages(
+      scoped_refptr<device::UsbDevice> device);
   void OnDeviceChecked(const std::string& guid, bool allowed);
   void DoRequestUserAuthorization(const std::string& guid,
                                   const std::string& package,