Add virtual destructor to UsbService::Observer

This patch added virtual destructor to UsbService::Observer.

Review URL: https://codereview.chromium.org/1310253006

Cr-Commit-Position: refs/heads/master@{#345210}

3 files changed, 6 insertions, 2 deletions

diff --git a/device/test/usb_test_gadget_impl.cc b/device/test/usb_test_gadget_impl.cc
index 26a318f..a94cb76 100644
--- a/device/test/usb_test_gadget_impl.cc
+++ b/device/test/usb_test_gadget_impl.cc
@@ -399,7 +399,7 @@ class DeviceAddListener : public UsbService::Observer {
         weak_factory_(this) {
     observer_.Add(usb_service_);
   }
-  virtual ~DeviceAddListener() {}
+  ~DeviceAddListener() override {}
 
   scoped_refptr<UsbDevice> WaitForAdd() {
     usb_service_->GetDevices(base::Bind(&DeviceAddListener::OnDevicesEnumerated,
@@ -465,7 +465,7 @@ class DeviceRemoveListener : public UsbService::Observer {
         weak_factory_(this) {
     observer_.Add(usb_service_);
   }
-  virtual ~DeviceRemoveListener() {}
+  ~DeviceRemoveListener() override {}
 
   void WaitForRemove() {
     usb_service_->GetDevices(
diff --git a/device/usb/usb_service.cc b/device/usb/usb_service.cc
index 99ad59b..9f9f02c2 100644
--- a/device/usb/usb_service.cc
+++ b/device/usb/usb_service.cc
@@ -18,6 +18,8 @@ UsbService* g_service;
 
 }  // namespace
 
+UsbService::Observer::~Observer() {}
+
 void UsbService::Observer::OnDeviceAdded(scoped_refptr<UsbDevice> device) {
 }
 
diff --git a/device/usb/usb_service.h b/device/usb/usb_service.h
index b185241..8e633d2 100644
--- a/device/usb/usb_service.h
+++ b/device/usb/usb_service.h
@@ -33,6 +33,8 @@ class UsbService : public base::NonThreadSafe {
 
   class Observer {
    public:
+    virtual ~Observer();
+
     // These events are delivered from the thread on which the UsbService object
     // was created.
     virtual void OnDeviceAdded(scoped_refptr<UsbDevice> device);