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

ui/gfx/gpu_memory_buffer.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 UI_GFX_GPU_MEMORY_BUFFER_H_
 #define UI_GFX_GPU_MEMORY_BUFFER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 71 matching lines @@
   virtual BufferFormat GetFormat() const = 0;
 
   // Fills the stride in bytes for each plane of the buffer. The stride of
   // plane K is stored at index K-1 of the |stride| array.
   virtual int stride(size_t plane) const = 0;
 
   // Set the color space in which this buffer should be interpreted when used
   // for scanout. Note that this will not impact texturing from the buffer.
   virtual void SetColorSpaceForScanout(const gfx::ColorSpace& color_space);
 
+  // Returns true if the GpuMemoryBuffer is currently being read by the
+  // WindowServer and should not be written to.
+  virtual bool IsInUseByMacOSWindowServer() const;
+
   // Returns a unique identifier associated with buffer.
   virtual GpuMemoryBufferId GetId() const = 0;
 
   // Returns a platform specific handle for this buffer.
   virtual GpuMemoryBufferHandle GetHandle() const = 0;
 
   // Type-checking downcast routine.
   virtual ClientBuffer AsClientBuffer() = 0;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GPU_MEMORY_BUFFER_H_