Refactor intra-strip panel drags by introducing PanelDragController.

chrome/browser/ui/panels/overflow_panel_strip.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 CHROME_BROWSER_UI_PANELS_OVERFLOW_PANEL_STRIP_H_
 #define CHROME_BROWSER_UI_PANELS_OVERFLOW_PANEL_STRIP_H_
 #pragma once
 
 #include <vector>
 #include "chrome/browser/ui/panels/panel.h"
@@ skipping 24 matching lines @@
   virtual void AddPanel(Panel* panel) OVERRIDE;
   virtual bool RemovePanel(Panel* panel) OVERRIDE;
   virtual void CloseAll() OVERRIDE;
   virtual void ResizePanelWindow(
       Panel* panel,
       const gfx::Size& preferred_window_size) OVERRIDE;
   virtual void OnPanelAttentionStateChanged(Panel* panel) OVERRIDE;
   virtual void ActivatePanel(Panel* panel) OVERRIDE;
   virtual void MinimizePanel(Panel* panel) OVERRIDE;
   virtual void RestorePanel(Panel* panel) OVERRIDE;
+  virtual bool CanDragPanel(const Panel* panel) const OVERRIDE;
+  virtual void StartDraggingPanel(Panel* panel) OVERRIDE;
+  virtual void DragPanel(Panel* panel, int delta_x, int delta_y) OVERRIDE;
+  virtual void EndDraggingPanel(Panel* panel, bool cancelled) OVERRIDE;
 
   void OnFullScreenModeChanged(bool is_full_screen);
 
   int num_panels() const { return static_cast<int>(panels_.size()); }
   Panel* first_panel() const {
     return panels_.empty() ? NULL : panels_.front();
   }
   const Panels& panels() const { return panels_; }
 
 #ifdef UNIT_TEST
@@ skipping 81 matching lines @@
   int overflow_hover_animator_start_width_;
   int overflow_hover_animator_end_width_;
 
   // Invalid panel index.
   static const size_t kInvalidPanelIndex = static_cast<size_t>(-1);
 
   DISALLOW_COPY_AND_ASSIGN(OverflowPanelStrip);
 };
 
 #endif  // CHROME_BROWSER_UI_PANELS_OVERFLOW_PANEL_STRIP_H_