views slider: Add support for gestures.

ui/views/controls/slider.h

 // Copyright (c) 2012 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 UI_VIEWS_CONTROLS_SLIDER_H_
 #define UI_VIEWS_CONTROLS_SLIDER_H_
 #pragma once
 
 #include "ui/base/animation/animation_delegate.h"
 #include "ui/views/view.h"
@@ skipping 43 matching lines @@
   void SetValue(float value);
 
   // Set the delta used for changing the value via keyboard.
   void SetKeyboardIncrement(float increment);
 
   void SetAccessibleName(const string16& name);
 
  private:
   void SetValueInternal(float value, SliderChangeReason reason);
 
+  // Moves the button to the specified point and updates the value accordingly.
+  void MoveButtonTo(const gfx::Point& point);
+
   // views::View overrides:
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
   virtual bool OnMousePressed(const views::MouseEvent& event) OVERRIDE;
   virtual bool OnMouseDragged(const views::MouseEvent& event) OVERRIDE;
   virtual void OnMouseReleased(const views::MouseEvent& event) OVERRIDE;
+  virtual ui::GestureStatus OnGestureEvent(
+      const views::GestureEvent& event) OVERRIDE;
   virtual bool OnKeyPressed(const views::KeyEvent& event) OVERRIDE;
   virtual void GetAccessibleState(ui::AccessibleViewState* state) OVERRIDE;
 
   // ui::AnimationDelegate overrides:
   virtual void AnimationProgressed(const ui::Animation* animation) OVERRIDE;
 
   SliderListener* listener_;
   Orientation orientation_;
 
   scoped_ptr<ui::SlideAnimation> move_animation_;
 
   float value_;
   float keyboard_increment_;
   float animating_value_;
   bool value_is_valid_;
   string16 accessible_name_;
 
   DISALLOW_COPY_AND_ASSIGN(Slider);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_SLIDER_H_