NOT for review (for discussion): Query IOSurfaceIsInUse in the browser process

ui/gfx/gpu_memory_buffer.cc

 // Copyright 2013 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/gpu_memory_buffer.h"
 
 namespace gfx {
 
 GpuMemoryBufferHandle::GpuMemoryBufferHandle()
     : type(EMPTY_BUFFER), id(0), handle(base::SharedMemory::NULLHandle()) {
 }
 
 GpuMemoryBufferHandle::GpuMemoryBufferHandle(
     const GpuMemoryBufferHandle& other) = default;
 
 GpuMemoryBufferHandle::~GpuMemoryBufferHandle() {}
 
 void GpuMemoryBuffer::SetColorSpaceForScanout(
     const gfx::ColorSpace& color_space) {}
 
+bool GpuMemoryBuffer::IsInUseByMacOSWindowServer() const {
+  return false;
+}
+
 }  // namespace gfx