content: Pass IOSurface references using Mach IPC.

content/common/mac/io_surface_manager.h

+// Copyright 2015 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 CONTENT_COMMON_MAC_IO_SURFACE_MANAGER_H_
+#define CONTENT_COMMON_MAC_IO_SURFACE_MANAGER_H_
+
+#include <IOSurface/IOSurfaceAPI.h>
+
+#include "content/common/content_export.h"
+
+namespace content {
+
+class CONTENT_EXPORT IOSurfaceManager {

[Robert Sesek, 2015/05/12 23:15:25]

This needs a class-level comment.

[reveman, 2015/05/15 14:48:57]

Done.

+ public:
+  static IOSurfaceManager* GetInstance();
+  static void InitInstance(IOSurfaceManager* instance);

[Robert Sesek, 2015/05/12 23:15:25]

SetInstance is probably a more appropriate name?

[reveman, 2015/05/15 14:48:57]

Done. Was InitInstance to be consistent with SurfaceTextureManager on Android
but I'll fix in a different patch as SetInstance makes more sense.

+
+  // Register an IO surface for use in another process.

[Robert Sesek, 2015/05/12 23:15:25]

How does an io_surface_id differ from a client_id?

[reveman, 2015/05/15 14:48:57]

client_id specifies what GPU client is allowed access the IOSurface. The mach
message handling in the browser process will enforce this. io_surface_id is a
unique ID that identifies each IOSurface and allows GPU clients to use multiple
IOSurfaces.

+  virtual bool RegisterIOSurface(int io_surface_id,
+                                 int client_id,
+                                 IOSurfaceRef io_surface) = 0;
+
+  // Unregister an IO surface previously registered for use in another
+  // process.
+  virtual void UnregisterIOSurface(int io_surface_id, int client_id) = 0;
+
+  // Acquire IO surface reference for a registered IO surface.
+  virtual IOSurfaceRef AcquireIOSurface(int io_surface_id) = 0;
+
+ protected:
+  virtual ~IOSurfaceManager() {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_MAC_IO_SURFACE_MANAGER_H_