Clean up HID backend and API.

device/hid/hid_service_linux.h

Index: device/hid/hid_service_linux.h
diff --git a/device/hid/hid_service_linux.h b/device/hid/hid_service_linux.h
index ba58fada58d0c059c012497c213c66762fae35a5..7b4d719f1d2293cde1861fed738b7d32f4a139a9 100644
--- a/device/hid/hid_service_linux.h
+++ b/device/hid/hid_service_linux.h
@@ -50,7 +50,8 @@ class HidServiceLinux : public HidService,
  public:
   HidServiceLinux();
 
-  virtual scoped_refptr<HidConnection> Connect(std::string device_id) OVERRIDE;
+  virtual scoped_refptr<HidConnection> Connect(const std::string& device_id)
+      OVERRIDE;
 
   // Implements base::MessagePumpLibevent::Watcher
   virtual void OnFileCanReadWithoutBlocking(int fd) OVERRIDE;
@@ -60,8 +61,8 @@ class HidServiceLinux : public HidService,
   virtual ~HidServiceLinux();
 
   void Enumerate();
-  void PlatformDeviceAdd(udev_device* device);
-  void PlatformDeviceRemove(udev_device* raw_dev);
+  void PlatformAddDevice(udev_device* device);
+  void PlatformRemoveDevice(udev_device* raw_dev);
 
   scoped_ptr<udev, UdevDeleter> udev_;
   scoped_ptr<udev_monitor, UdevMonitorDeleter> monitor_;