exo: Implement zcr_linux_explicit_synchronization_v1

components/exo/display.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 COMPONENTS_EXO_DISPLAY_H_
 #define COMPONENTS_EXO_DISPLAY_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/shared_memory_handle.h"
 
 #if defined(USE_OZONE)
 #include "base/files/scoped_file.h"
 #include "ui/gfx/buffer_types.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/native_pixmap_handle.h"
 #endif
 
 namespace gfx {
+class GpuFence;
 class Point;
 }
 
 namespace exo {
 class NotificationSurface;
 class NotificationSurfaceManager;
 class SharedMemory;
 class ShellSurface;
 class SubSurface;
 class Surface;
@@ skipping 20 matching lines @@
       const base::SharedMemoryHandle& handle,
       size_t size);
 
 #if defined(USE_OZONE)
   // Creates a buffer for a Linux DMA-buf file descriptor.
   std::unique_ptr<Buffer> CreateLinuxDMABufBuffer(
       const gfx::Size& size,
       gfx::BufferFormat format,
       const std::vector<gfx::NativePixmapPlane>& planes,
       std::vector<base::ScopedFD>&& fds);
+
+  std::unique_ptr<gfx::GpuFence> CreateLinuxFence(

[reveman, 2016/10/12 19:20:19]

nit: "// Creates a GpuFence for a Linux fence file descriptor." above this just
to be consistent with CreateLinuxDMABufBuffer.

+      base::ScopedFD& fd

[reveman, 2016/10/12 19:20:19]

nit: remove "&" as base::ScopedFD is preferably passed by value

+  );
 #endif
 
   // Creates a shell surface for an existing surface.
   std::unique_ptr<ShellSurface> CreateShellSurface(Surface* surface);
 
   // Creates a popup shell surface for an existing surface at |position| and
   // with |parent|. |position| is in |parent| surface local coordinates.
   std::unique_ptr<ShellSurface> CreatePopupShellSurface(
       Surface* surface,
       ShellSurface* parent,
@@ skipping 15 matching lines @@
 
  private:
   NotificationSurfaceManager* const notification_surface_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(Display);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_DISPLAY_H_