Clean up HID backend and API.

device/hid/hid_service_linux.cc

Index: device/hid/hid_service_linux.cc
diff --git a/device/hid/hid_service_linux.cc b/device/hid/hid_service_linux.cc
index f02a550e5a9d3822f9c7e8035fcd379499d3807e..812228909f9d73e4934e663da503ac51fe0824a7 100644
--- a/device/hid/hid_service_linux.cc
+++ b/device/hid/hid_service_linux.cc
@@ -110,14 +110,14 @@ void HidServiceLinux::Enumerate() {
     ScopedUdevDevicePtr hid_dev(
         udev_device_new_from_syspath(udev_.get(), udev_list_entry_get_name(i)));
     if (hid_dev) {
-      PlatformDeviceAdd(hid_dev.get());
+      PlatformAddDevice(hid_dev.get());
     }
   }
 
   initialized_ = true;
 }
 
-void HidServiceLinux::PlatformDeviceAdd(udev_device* device) {
+void HidServiceLinux::PlatformAddDevice(udev_device* device) {
   if (!device)
     return;
 
@@ -161,7 +161,7 @@ void HidServiceLinux::PlatformDeviceAdd(udev_device* device) {
   AddDevice(device_info);
 }
 
-void HidServiceLinux::PlatformDeviceRemove(udev_device* raw_dev) {
+void HidServiceLinux::PlatformRemoveDevice(udev_device* raw_dev) {
   // The returned the device is not referenced.
   udev_device* hid_dev =
       udev_device_get_parent_with_subsystem_devtype(raw_dev, "hid", NULL);
@@ -177,7 +177,8 @@ void HidServiceLinux::PlatformDeviceRemove(udev_device* raw_dev) {
   RemoveDevice(device_id);
 }
 
-scoped_refptr<HidConnection> HidServiceLinux::Connect(std::string device_id) {
+scoped_refptr<HidConnection> HidServiceLinux::Connect(
+    const std::string& device_id) {
   if (!ContainsKey(devices_, device_id))
     return NULL;
   ScopedUdevDevicePtr hid_device(
@@ -200,9 +201,9 @@ void HidServiceLinux::OnFileCanReadWithoutBlocking(int fd) {
 
   std::string action(udev_device_get_action(dev.get()));
   if (action == kUdevActionAdd) {
-    PlatformDeviceAdd(dev.get());
+    PlatformAddDevice(dev.get());
   } else if (action == kUdevActionRemove) {
-    PlatformDeviceRemove(dev.get());
+    PlatformRemoveDevice(dev.get());
   }
 }