Make the device::HidService destructor protected.

This prevents anything other than device::HidService::Destroyer from
calling the destructor. For example, scoped_ptr, as was the case in
HidConnectionTest.

BUG=

Review URL: https://codereview.chromium.org/542153004

Cr-Commit-Position: refs/heads/master@{#293623}

1 files changed, 3 insertions, 2 deletions

diff --git a/device/hid/hid_service.h b/device/hid/hid_service.h
index cc7813b..c370203 100644
--- a/device/hid/hid_service.h
+++ b/device/hid/hid_service.h
@@ -23,8 +23,6 @@ class HidService {
   static HidService* GetInstance(
       scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
 
-  virtual ~HidService();
-
   // Enumerates and returns a list of device identifiers.
   virtual void GetDevices(std::vector<HidDeviceInfo>* devices);
 
@@ -41,6 +39,7 @@ class HidService {
   typedef std::map<HidDeviceId, HidDeviceInfo> DeviceMap;
 
   HidService();
+  virtual ~HidService();
 
   void AddDevice(const HidDeviceInfo& info);
   void RemoveDevice(const HidDeviceId& device_id);
@@ -49,6 +48,8 @@ class HidService {
   base::ThreadChecker thread_checker_;
 
  private:
+  class Destroyer;
+
   DeviceMap devices_;
 
   DISALLOW_COPY_AND_ASSIGN(HidService);