Clean up HID backend and API.

device/hid/hid_service.h

-// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DEVICE_HID_HID_SERVICE_H_
 #define DEVICE_HID_HID_SERVICE_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
-#include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
-#include "base/strings/string16.h"
 #include "base/threading/thread_checker.h"
-#include "build/build_config.h"
 #include "device/hid/hid_device_info.h"
 
 namespace device {
 
-namespace {
-
-class HidServiceContainer;
-
-}  // namespace
-
 class HidConnection;
-class HidService;
 
 class HidService : public base::MessageLoop::DestructionObserver {
  public:
   // Must be called on FILE thread.
   static HidService* GetInstance();
 
   // Enumerates and returns a list of device identifiers.
   virtual void GetDevices(std::vector<HidDeviceInfo>* devices);
 
   // Fills in the device info struct of the given device_id.
   // Returns true if succeed.
   // Returns false if the device_id is invalid, with info untouched.
-  bool GetInfo(std::string device_id, HidDeviceInfo* info) const;
+  bool GetInfo(HidDeviceId device_id, HidDeviceInfo* info) const;
 
-  virtual scoped_refptr<HidConnection> Connect(
-      std::string platform_device_id) = 0;
+  virtual scoped_refptr<HidConnection> Connect(HidDeviceId device_id) = 0;
 
   // Implements base::MessageLoop::DestructionObserver
   virtual void WillDestroyCurrentMessageLoop() OVERRIDE;
 
-  // Gets whether the HidService have been successfully initialized.
-  bool initialized() const { return initialized_; }
-
  protected:
-  friend class HidServiceContainer;
   friend struct base::DefaultDeleter<HidService>;
   friend class HidConnectionTest;
 
+  typedef std::map<HidDeviceId, HidDeviceInfo> DeviceMap;
+
   HidService();
   virtual ~HidService();
 
   static HidService* CreateInstance();
 
-  virtual void AddDevice(HidDeviceInfo info);
-  virtual void RemoveDevice(std::string platform_device_id);
+  HidDeviceId GenerateDeviceId();
 
-  typedef std::map<std::string, HidDeviceInfo> DeviceMap;
+  void AddDevice(const HidDeviceInfo& info);
+  void RemoveDevice(HidDeviceId device_id);
+
+  base::ThreadChecker thread_checker_;

[Mark Mentovai, 2014/02/21 17:48:18]

Here’s a case where the thread checker is shared by the base class and its
subclasses, and I think we can relax the rule about protected member variables
for this one because the thread checker isn’t conceptually data.

+
+ private:
   DeviceMap devices_;
 
-  bool initialized_;
-
-  base::ThreadChecker thread_checker_;
+  HidDeviceId next_device_id_;
 
   DISALLOW_COPY_AND_ASSIGN(HidService);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_HID_HID_SERVICE_H_