Clarify usage of smart pointers

- Members should be smart (shared or unique)
- Prefer function args to be bare, unless the arg is intended to be
  stored by the callee
- Function args that are smart should be const refs to avoid an extra
  copy

Change-Id: I8052fa432bcffbabff9d67a8d568640cac64d4ad
diff --git a/modules/input/evdev/InputHub.h b/modules/input/evdev/InputHub.h
index bec327a..dfab3db 100644
--- a/modules/input/evdev/InputHub.h
+++ b/modules/input/evdev/InputHub.h
@@ -89,10 +89,10 @@
 /** Callback interface for receiving input events, including device changes. */
 class InputCallbackInterface {
 public:
-    virtual void onInputEvent(std::shared_ptr<InputDeviceNode> node, InputEvent& event,
+    virtual void onInputEvent(const std::shared_ptr<InputDeviceNode>& node, InputEvent& event,
             nsecs_t event_time) = 0;
-    virtual void onDeviceAdded(std::shared_ptr<InputDeviceNode> node) = 0;
-    virtual void onDeviceRemoved(std::shared_ptr<InputDeviceNode> node) = 0;
+    virtual void onDeviceAdded(const std::shared_ptr<InputDeviceNode>& node) = 0;
+    virtual void onDeviceRemoved(const std::shared_ptr<InputDeviceNode>& node) = 0;
 
 protected:
     InputCallbackInterface() = default;
@@ -129,7 +129,7 @@
  */
 class InputHub : public InputHubInterface {
 public:
-    explicit InputHub(std::shared_ptr<InputCallbackInterface> cb);
+    explicit InputHub(const std::shared_ptr<InputCallbackInterface>& cb);
     virtual ~InputHub() override;
 
     virtual status_t registerDevicePath(const std::string& path) override;
@@ -143,8 +143,8 @@
 private:
     status_t readNotify();
     status_t scanDir(const std::string& path);
-    status_t openNode(const std::string& path, std::shared_ptr<InputDeviceNode>* outNode);
-    status_t closeNode(const std::shared_ptr<InputDeviceNode>& node);
+    std::shared_ptr<InputDeviceNode> openNode(const std::string& path);
+    status_t closeNode(const InputDeviceNode* node);
     status_t closeNodeByFd(int fd);
     std::shared_ptr<InputDeviceNode> findNodeByPath(const std::string& path);