Adds a class that makes it easy to subclass a HWND and filter messages sent to it.

ui/gfx/blit.cc

 // 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.
 
 #include "ui/gfx/blit.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
 #include "skia/ext/platform_canvas.h"
 #include "ui/gfx/point.h"
@@ skipping 108 matching lines @@
                         SkCanvas *src_canvas,
                         const Point& src_origin) {
   DCHECK(skia::SupportsPlatformPaint(dst_canvas));
   DCHECK(skia::SupportsPlatformPaint(src_canvas));
   BlitContextToContext(skia::BeginPlatformPaint(dst_canvas), dst_rect,
                        skia::BeginPlatformPaint(src_canvas), src_origin);
   skia::EndPlatformPaint(src_canvas);
   skia::EndPlatformPaint(dst_canvas);
 }
 
-#if defined(OS_WIN)
+#if defined(OS_WIN) && !defined(USE_AURA)
 
 void ScrollCanvas(SkCanvas* canvas,
                   const gfx::Rect& clip,
                   const gfx::Point& amount) {
   DCHECK(!HasClipOrTransform(*canvas));  // Don't support special stuff.
   DCHECK(skia::SupportsPlatformPaint(canvas));
   skia::ScopedPlatformPaint scoped_platform_paint(canvas);
   HDC hdc = scoped_platform_paint.GetPlatformSurface();
 
   RECT damaged_rect;
   RECT r = clip.ToRECT();
   ScrollDC(hdc, amount.x(), amount.y(), NULL, &r, NULL, &damaged_rect);
 }
 
-#elif defined(OS_POSIX)
+#elif defined(OS_POSIX) || defined(USE_AURA)
 // Cairo has no nice scroll function so we do our own. On Mac it's possible to
 // use platform scroll code, but it's complex so we just use the same path
 // here. Either way it will be software-only, so it shouldn't matter much.
 
 void ScrollCanvas(SkCanvas* canvas,
                   const gfx::Rect& in_clip,
                   const gfx::Point& amount) {
   DCHECK(!HasClipOrTransform(*canvas));  // Don't support special stuff.
   SkBitmap& bitmap = const_cast<SkBitmap&>(
       skia::GetTopDevice(*canvas)->accessBitmap(true));
@@ skipping 37 matching lines @@
       memmove(bitmap.getAddr32(dest_rect.x(), dest_rect.y() + y),
               bitmap.getAddr32(src_rect.x(), src_rect.y() + y),
               row_bytes);
     }
   }
 }
 
 #endif
 
 }  // namespace gfx