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

gpu/ipc/client/gpu_memory_buffer_impl_io_surface.h

 // 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.
 
 #ifndef GPU_IPC_CLIENT_GPU_MEMORY_BUFFER_IMPL_IO_SURFACE_H_
 #define GPU_IPC_CLIENT_GPU_MEMORY_BUFFER_IMPL_IO_SURFACE_H_
 
 #include <IOSurface/IOSurface.h>
 #include <stddef.h>
 #include <stdint.h>
@@ skipping 27 matching lines @@
                                           gfx::BufferFormat format,
                                           gfx::BufferUsage usage,
                                           gfx::GpuMemoryBufferHandle* handle);
 
   // Overridden from gfx::GpuMemoryBuffer:
   bool Map() override;
   void* memory(size_t plane) override;
   void Unmap() override;
   int stride(size_t plane) const override;
   void SetColorSpaceForScanout(const gfx::ColorSpace& color_space) override;
+  bool IsInUseByMacOSWindowServer() const override;
   gfx::GpuMemoryBufferHandle GetHandle() const override;
 
  private:
   GpuMemoryBufferImplIOSurface(gfx::GpuMemoryBufferId id,
                                const gfx::Size& size,
                                gfx::BufferFormat format,
                                const DestructionCallback& callback,
                                IOSurfaceRef io_surface,
                                uint32_t lock_flags);
 
   base::ScopedCFTypeRef<IOSurfaceRef> io_surface_;
   uint32_t lock_flags_;
   // Cache the color space, because re-assigning the same value can be
   // expensive.
   gfx::ColorSpace color_space_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferImplIOSurface);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_IPC_CLIENT_GPU_MEMORY_BUFFER_IMPL_IO_SURFACE_H_