Add the "virtual" keyword on method overrides that are missing it.

chrome/browser/gtk/slide_animator_gtk.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.
 //
 // A helper class for animating the display of native widget content.
 // Currently only handle vertical sliding, but could be extended to handle
 // horizontal slides or other types of animations.
 //
 // NOTE: This does not handle clipping. If you are not careful, you will
 // wind up with visibly overlapping widgets. If you need clipping, you can
@@ skipping 65 matching lines @@
   bool IsShowing();
 
   // Returns whether the widget is currently showing the close animation.
   bool IsClosing();
 
   // Returns whether the widget is currently showing the open or close
   // animation.
   bool IsAnimating();
 
   // AnimationDelegate implementation.
-  void AnimationProgressed(const Animation* animation);
-  void AnimationEnded(const Animation* animation);
+  virtual void AnimationProgressed(const Animation* animation);
+  virtual void AnimationEnded(const Animation* animation);
 
   // Used during testing; disable or enable animations (default is enabled).
   static void SetAnimationsForTesting(bool enable);
 
  private:
   static void OnChildSizeAllocate(GtkWidget* child,
                                   GtkAllocation* allocation,
                                   SlideAnimatorGtk* slider);
 
   scoped_ptr<SlideAnimation> animation_;
@@ skipping 14 matching lines @@
   // We need to move the child widget to (0, -height), but we don't know its
   // height until it has been allocated. This variable will be true until the
   // child widget has been allocated, at which point we will move it, and then
   // set this variable to false to indicate it should not be moved again.
   bool child_needs_move_;
 
   static bool animations_enabled_;
 };
 
 #endif  // CHROME_BROWSER_GTK_SLIDE_ANIMATOR_GTK_H_