Free the dibsection (HBITMAP) in PlatformBitmap's destructor, so we don't leak!

skia/ext/platform_canvas.h

 // Copyright (c) 2011 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_PLATFORM_CANVAS_H_
 #define SKIA_EXT_PLATFORM_CANVAS_H_
 
 // The platform-specific device will include the necessary platform headers
 // to get the surface type.
 #include "base/basictypes.h"
@@ skipping 151 matching lines @@
 
   // Returns the platform surface, or 0 if Allocate() did not return true.
   PlatformSurface GetSurface() { return surface_; }
 
   // Return the skia bitmap, which will be empty if Allocate() did not
   // return true.
   const SkBitmap& GetBitmap() { return bitmap_; }
 
  private:
   SkBitmap bitmap_;
-  PlatformSurface surface_;
+  PlatformSurface surface_; // initialized to 0
+  intptr_t platform_extra_; // initialized to 0, specific to each platform
 
   DISALLOW_COPY_AND_ASSIGN(PlatformBitmap);
 };
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_CANVAS_H_