Support browser side thumbnailing for GPU composited pages on Windows.

content/browser/gpu/gpu_surface_reader_win.cc

+// Copyright (c) 2012 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 "content/browser/gpu/gpu_surface_reader_win.h"
+
+#include "ui/gfx/surface/accelerated_surface_win.h"
+
+
+GpuSurfaceReader::GpuSurfaceReader() {
+}
+
+GpuSurfaceReader::~GpuSurfaceReader() {
+}
+
+bool GpuSurfaceReader::CopySurface(
+    const GpuSurfaceTracker::SurfaceInfo& surface_info,
+    const gfx::Size& size,
+    std::vector<unsigned char>* out) {
+  if (!surface_info.handle.accelerated_surface)

[apatrick_chromium, 2012/03/07 20:39:37]

Alternatively, given how simple it is, why not just move this into
GpuSurfaceTracker, perhaps with a platform specific gpu_surface_tracker_win.cc
if this ever becomes non-trivial?

[mazda, 2012/03/08 13:14:28]

Moved the code to RenderWidgetHostViewWin.

+    return false;
+  return surface_info.handle.accelerated_surface->CopyTo(size, out);
+}