[8/8][Ozone-Dri] Pass DRM FD to GPU process on hotplug event

ui/ozone/platform/dri/drm_device_generator.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 UI_OZONE_PLATFORM_DRI_DRM_DEVICE_GENERATOR_H_
+#define UI_OZONE_PLATFORM_DRI_DRM_DEVICE_GENERATOR_H_
+
+#include "base/files/file.h"
+#include "base/memory/ref_counted.h"
+
+namespace ui {
+
+class DriWrapper;
+
+class DrmDeviceGenerator {
+ public:
+  DrmDeviceGenerator();
+  virtual ~DrmDeviceGenerator();
+
+  virtual scoped_refptr<DriWrapper> CreateDevice(

[jln (very slow on Chromium), 2015/02/19 01:28:58]

Could you add a comment here? (I'm sure this will become clear as I go further
in the review, but it we would be nice to understand on its own).

[dnicoara, 2015/02/19 02:42:52]

Done.

Just to explain further: there are 2 platforms that share much of the code (DRM
and GBM). The device generator is here just to allow us to create share much of
the code, but create different devices depending on the platform used.

DRM uses the basic DRM API to allocate buffers and map them so that we can paint
into them using Skia. This is used for software rendering. GBM builds on top of
DRM and allows us to allocate buffers that will be used with EGL and GLES2 for
accelerated rendering.

+      const base::FilePath& device_path,
+      base::File file);
+
+ public:
+  DISALLOW_COPY_AND_ASSIGN(DrmDeviceGenerator);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PLATFORM_DRI_DRM_DEVICE_GENERATOR_H_