Give classes with virtual methods virtual protected destructors instead of implicit non-virtual public destructors.

Was originally:
Replace public nonvirtual destructors in classes with virtual members
with protected nonvirtual destructors where possible, and with
public virtual destructors where destruction of a derived class occurs.
(Excluding chrome/browser/...)

(Part 4 of http://www.gotw.ca/publications/mill18.htm
has a rationale for why public nonvirtual destructors in classes with
virtual members is dangerous.)

Patch by: Jacob Mandelson (jlmjln@gmail.com)
BUG=none
TEST=base_unittests & app_unittests

Review URL: http://codereview.chromium.org/200106

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34633 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 19 insertions, 2 deletions

diff --git a/app/animation.h b/app/animation.h
index e6877b6..bd38fb4 100644
--- a/app/animation.h
+++ b/app/animation.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// 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.
 // Inspired by NSAnimation
@@ -33,6 +33,9 @@ class AnimationDelegate {
   // Called when an animation has been canceled.
   virtual void AnimationCanceled(const Animation* animation) {
   }
+
+ protected:
+  virtual ~AnimationDelegate() {}
 };
 
 // Animation
diff --git a/app/table_model.h b/app/table_model.h
index c1e61b1..02d86dd 100644
--- a/app/table_model.h
+++ b/app/table_model.h
@@ -94,6 +94,8 @@ class TableModel {
   void ClearCollator();
 
  protected:
+  virtual ~TableModel() {}
+
   // Returns the collator used by CompareValues.
   icu::Collator* GetCollator();
 };
diff --git a/app/table_model_observer.h b/app/table_model_observer.h
index fcd50f4..cbf0d5d 100644
--- a/app/table_model_observer.h
+++ b/app/table_model_observer.h
@@ -20,6 +20,9 @@ class TableModelObserver {
 
   // Invoked when a range of items has been removed.
   virtual void OnItemsRemoved(int start, int length) = 0;
+
+ protected:
+  virtual ~TableModelObserver() {}
 };
 
 #endif  // APP_TABLE_MODEL_OBSERVER_H_
diff --git a/app/tree_model.h b/app/tree_model.h
index 882c82f..86d6424 100644
--- a/app/tree_model.h
+++ b/app/tree_model.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -21,6 +21,9 @@ class TreeModelNode {
  public:
   // Returns the title for the node.
   virtual const std::wstring& GetTitle() const = 0;
+
+ protected:
+  virtual ~TreeModelNode() {}
 };
 
 // Observer for the TreeModel. Notified of significant events to the model.
@@ -45,6 +48,9 @@ class TreeModelObserver {
 
   // Notification that the contents of a node has changed.
   virtual void TreeNodeChanged(TreeModel* model, TreeModelNode* node) = 0;
+
+ protected:
+  virtual ~TreeModelObserver() {}
 };
 
 // TreeModel ------------------------------------------------------------------
@@ -86,6 +92,9 @@ class TreeModel {
   // default icon. The index is relative to the list of icons returned from
   // GetIcons.
   virtual int GetIconIndex(TreeModelNode* node) { return -1; }
+
+ protected:
+  virtual ~TreeModel() {}
 };
 
 #endif  // APP_TREE_MODEL_H_