Replace IOSurfaceManager by directly passing IOSurface Mach ports over Chrome IPC.

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 "base/memory/shared_memory.h"
 #include "base/trace_event/memory_dump_manager.h"
 #include "build/build_config.h"
 #include "ui/gfx/buffer_types.h"
 #include "ui/gfx/generic_shared_memory_id.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/gfx_export.h"
 
 #if defined(USE_OZONE)
 #include "ui/gfx/native_pixmap_handle_ozone.h"
+#elif defined(OS_MACOSX)
+#include "base/mac/scoped_mach_port.h"
 #endif
 
 extern "C" typedef struct _ClientBuffer* ClientBuffer;
 
 namespace gfx {
 
 enum GpuMemoryBufferType {
   EMPTY_BUFFER,
   SHARED_MEMORY_BUFFER,
   IO_SURFACE_BUFFER,
   SURFACE_TEXTURE_BUFFER,
   OZONE_NATIVE_PIXMAP,
   GPU_MEMORY_BUFFER_TYPE_LAST = OZONE_NATIVE_PIXMAP
 };
 
 using GpuMemoryBufferId = GenericSharedMemoryId;
 
 struct GFX_EXPORT GpuMemoryBufferHandle {
   GpuMemoryBufferHandle();
+  ~GpuMemoryBufferHandle();
   bool is_null() const { return type == EMPTY_BUFFER; }
   GpuMemoryBufferType type;
   GpuMemoryBufferId id;
   base::SharedMemoryHandle handle;
   uint32_t offset;
   int32_t stride;
 #if defined(USE_OZONE)
   NativePixmapHandle native_pixmap_handle;
+#elif defined(OS_MACOSX)
+  base::mac::ScopedRefCountedMachSendRight mach_port;

[ccameron, 2015/12/21 19:30:14]

The existence of this port will result in the IOSurface being seen as "in use"
for as long as any GpuMemoryBufferHandle to that IOSurface exists in any
process.

This appears to be okay, but we will need to be careful to not hold
GpuMemoryBufferHandles around any longer than they are needed (e.g, if the
renderer which owns a GMB were to cache a handle to it, the result would be that
it would always look that the GMB were in use by the system).

 #endif
 };
 
 base::trace_event::MemoryAllocatorDumpGuid GFX_EXPORT
 GetGpuMemoryBufferGUIDForTracing(uint64 tracing_process_id,
                                  GpuMemoryBufferId buffer_id);
 
 // This interface typically correspond to a type of shared memory that is also
 // shared with the GPU. A GPU memory buffer can be written to directly by
 // regular CPU code, but can also be read by the GPU.
@@ skipping 31 matching lines @@
   // 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_