Improve performance of dragged tab renderering....

chrome/browser/gtk/tabs/dragged_tab_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.
 
 #ifndef CHROME_BROWSER_GTK_TABS_DRAGGED_TAB_GTK_H_
 #define CHROME_BROWSER_GTK_TABS_DRAGGED_TAB_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include "app/gfx/canvas.h"
@@ skipping 68 matching lines @@
   // transparent.
   void SetContainerColorMap();
 
   // Sets full transparency for the container window.  This is used if
   // compositing is available for the screen.
   void SetContainerTransparency();
 
   // Sets the shape mask for the container window to emulate a transparent
   // container window.  This is used if compositing is not available for the
   // screen.
-  void SetContainerShapeMask(const SkBitmap& dragged_contents);
+  // |pixbuf| is the pixbuf for the tab only (not the render view).
+  void SetContainerShapeMask(GdkPixbuf* pixbuf);
 
-  // Paints the tab when it's attached to a tabstrip.
-  SkBitmap PaintAttachedTab();
-
-  // Paints the tab when it's not attached to any tabstrip.
-  SkBitmap PaintDetachedView();
-
-  // Paints a screenshot of the dragged contents from the backing store into
-  // |canvas|.
-  void PaintScreenshotIntoCanvas(gfx::Canvas* canvas,
-                                 const gfx::Rect& target_bounds);
+  // Paints the tab. The returned pixbuf belongs to the caller.
+  GdkPixbuf* PaintTab();
 
   // expose-event handler that notifies when the tab needs to be redrawn.
   static gboolean OnExposeEvent(GtkWidget* widget, GdkEventExpose* event,
                                 DraggedTabGtk* dragged_tab);
 
   // The window that contains the dragged tab or tab contents.
   GtkWidget* container_;
 
   // The native view of the tab contents.
   GtkWidget* contents_;
@@ skipping 29 matching lines @@
   scoped_ptr<Callback0::Type> animation_callback_;
 
   // The start and end bounds of the animation sequence.
   gfx::Rect animation_start_bounds_;
   gfx::Rect animation_end_bounds_;
 
   DISALLOW_COPY_AND_ASSIGN(DraggedTabGtk);
 };
 
 #endif  // CHROME_BROWSER_GTK_TABS_DRAGGED_TAB_GTK_H_