Implement drag and drop testing in a platform independent way.

chrome/browser/ui/panels/panel_browser_window_cocoa.h

Index: chrome/browser/ui/panels/panel_browser_window_cocoa.h
diff --git a/chrome/browser/ui/panels/panel_browser_window_cocoa.h b/chrome/browser/ui/panels/panel_browser_window_cocoa.h
index 74160a8385dd1f20cedc92dcad37cb3c2a7af8d0..0446dcf94dbb20e04c835c4ca75fd915b6650cfa 100644
--- a/chrome/browser/ui/panels/panel_browser_window_cocoa.h
+++ b/chrome/browser/ui/panels/panel_browser_window_cocoa.h
@@ -19,8 +19,7 @@ class Panel;
 // Bridges between C++ and the Cocoa NSWindow. Cross-platform code will
 // interact with this object when it needs to manipulate the window.
 
-class PanelBrowserWindowCocoa : public NativePanel,
-                                public NativePanelTesting {
+class PanelBrowserWindowCocoa : public NativePanel {
  public:
   PanelBrowserWindowCocoa(Browser* browser, Panel* panel,
                           const gfx::Rect& bounds);
@@ -48,7 +47,6 @@ class PanelBrowserWindowCocoa : public NativePanel,
   virtual bool IsDrawingAttention() const OVERRIDE;
   virtual Browser* GetPanelBrowser() const OVERRIDE;
   virtual void DestroyPanelBrowser() OVERRIDE;
-  virtual NativePanelTesting* GetNativePanelTesting() OVERRIDE;
 
   Panel* panel() { return panel_.get(); }
   Browser* browser() const { return browser_.get(); }