Add undeclared virtual destructors part 2...

chrome_frame/np_event_listener.h

 // Copyright (c) 2009 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 CHROME_FRAME_NP_EVENT_LISTENER_H_
 #define CHROME_FRAME_NP_EVENT_LISTENER_H_
 
 #include "base/logging.h"
 
 #include "chrome_frame/utils.h"
@@ skipping 15 matching lines @@
 class NpEventListener {
  public:
   NS_IMETHOD_(nsrefcnt) AddRef() = 0;
   NS_IMETHOD_(nsrefcnt) Release() = 0;
   virtual bool Subscribe(NPP instance,
                          const char* event_names[],
                          int event_name_count) = 0;
   virtual bool Unsubscribe(NPP instance,
                            const char* event_names[],
                            int event_name_count) = 0;
+
+ protected:
+  virtual ~NpEventListener() {}
 };
 
 // A little helper class to implement simple ref counting
 // and assert on single threadedness.
 template <class T>
 class NpEventListenerBase : public NpEventListener {
  public:
-  NpEventListenerBase(NpEventDelegate* delegate)
+  explicit NpEventListenerBase(NpEventDelegate* delegate)
       : ref_count_(0), delegate_(delegate) {
     DCHECK(delegate_);
     thread_id_ = ::GetCurrentThreadId();
   }
 
   ~NpEventListenerBase() {
     DCHECK(thread_id_ == ::GetCurrentThreadId());
   }
 
   NS_IMETHOD_(nsrefcnt) AddRef() {
@@ skipping 22 matching lines @@
   // used to DCHECK on expected single-threaded usage
   unsigned long thread_id_;
 };
 
 // Implements nsIDOMEventListener in order to receive events from DOM
 // elements inside an HTML page.
 class DomEventListener
   : public nsIDOMEventListener,
   public NpEventListenerBase<DomEventListener> {
  public:
-  DomEventListener(NpEventDelegate* delegate);
-  ~DomEventListener();
+  explicit DomEventListener(NpEventDelegate* delegate);
+  virtual ~DomEventListener();
 
   // Implementation of NpEventListener
   virtual bool Subscribe(NPP instance,
                          const char* event_names[],
                          int event_name_count);
   virtual bool Unsubscribe(NPP instance,
                            const char* event_names[],
                            int event_name_count);
  protected:
   // We implement QueryInterface etc ourselves in order to avoid
@@ skipping 13 matching lines @@
  private:
   static bool GetObjectElement(NPP instance, nsIDOMElement** element);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DomEventListener);
 };
 
 class NPObjectEventListener
   : public NpEventListenerBase<NPObjectEventListener> {
  public:
-  NPObjectEventListener(NpEventDelegate* delegate);
+  explicit NPObjectEventListener(NpEventDelegate* delegate);
   ~NPObjectEventListener();
 
   // Implementation of NpEventListener
   virtual bool Subscribe(NPP instance,
                          const char* event_names[],
                          int event_name_count);
   virtual bool Unsubscribe(NPP instance,
                            const char* event_names[],
                            int event_name_count);
 
  protected:
   // NPObject structure which is exposed by NPObjectEventListener.
   class Npo : public NPObject {
    public:
-    Npo(NPP npp) : npp_(npp), listener_(NULL) {
+    explicit Npo(NPP npp) : npp_(npp), listener_(NULL) {
     }
 
     void Initialize(NPObjectEventListener* listener) {
       listener_ = listener;
     }
 
     inline NPObjectEventListener* listener() const {
       return listener_;
     }
 
@@ skipping 31 matching lines @@
   static NPObject* GetObjectElement(NPP instance);
 
  private:
   // Our NPObject.
   ScopedNpObject<Npo> npo_;
 
   DISALLOW_COPY_AND_ASSIGN(NPObjectEventListener);
 };
 
 #endif  // CHROME_FRAME_NP_EVENT_LISTENER_H_