Basic windowless plugins, try 2.

skia/ext/bitmap_platform_device_linux.h

 // Copyright (c) 2006-2008 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 SKIA_EXT_BITMAP_PLATFORM_DEVICE_LINUX_H_
 #define SKIA_EXT_BITMAP_PLATFORM_DEVICE_LINUX_H_
 
 #include "base/ref_counted.h"
 #include "skia/ext/platform_device_linux.h"
 
@@ skipping 67 matching lines @@
                             BitmapPlatformDeviceLinuxData* data);
   virtual ~BitmapPlatformDeviceLinux();
   BitmapPlatformDeviceLinux& operator=(const BitmapPlatformDeviceLinux& other);
 
   // A stub copy constructor.  Needs to be properly implemented.
   BitmapPlatformDeviceLinux(const BitmapPlatformDeviceLinux& other);
 
   // Bitmaps aren't vector graphics.
   virtual bool IsVectorial() { return false; }
 
+  // If someone wants to paint on a Cairo surface version of our
+  // buffer, then give them the surface we're already using.
+  virtual cairo_surface_t* beginPlatformPaint() { return surface(); }
+
   cairo_surface_t* surface() const;
 
  private:
   scoped_refptr<BitmapPlatformDeviceLinuxData> data_;
 };
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_BITMAP_PLATFORM_DEVICE_LINUX_H_