[Ozone-Dri] Decouple the IO helper thread from DriWrapper

ui/ozone/platform/dri/dri_wrapper.h

 // Copyright 2014 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_DRI_WRAPPER_H_
 #define UI_OZONE_PLATFORM_DRI_DRI_WRAPPER_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
-#include "base/threading/thread.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/overlay_transform.h"
 #include "ui/ozone/platform/dri/hardware_display_plane_manager.h"
 #include "ui/ozone/platform/dri/scoped_drm_types.h"
 
 typedef struct _drmEventContext drmEventContext;
 typedef struct _drmModeModeInfo drmModeModeInfo;
 
 struct SkImageInfo;
 
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
 namespace ui {
 
 class HardwareDisplayPlaneManager;
 
 // Wraps DRM calls into a nice interface. Used to provide different
 // implementations of the DRM calls. For the actual implementation the DRM API
 // would be called. In unit tests this interface would be stubbed.
 class DriWrapper {
  public:
   typedef base::Callback<void(unsigned int /* frame */,
                               unsigned int /* seconds */,
                               unsigned int /* useconds */)> PageFlipCallback;
 
-  DriWrapper(const char* device_path, bool use_sync_flips);
+  DriWrapper(const char* device_path);
   virtual ~DriWrapper();
 
   // Open device.
   virtual void Initialize();
 
+  // |task_runner| will be used to asynchronously page flip.
+  virtual void InitializeTaskRunner(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+
   // Get the CRTC state. This is generally used to save state before using the
   // CRTC. When the user finishes using the CRTC, the user should restore the
   // CRTC to it's initial state. Use |SetCrtc| to restore the state.
   virtual ScopedDrmCrtcPtr GetCrtc(uint32_t crtc_id);
 
   // Used to configure CRTC with ID |crtc_id| to use the connector in
   // |connectors|. The CRTC will be configured with mode |mode| and will display
   // the framebuffer with ID |framebuffer|. Before being able to display the
   // framebuffer, it should be registered with the CRTC using |AddFramebuffer|.
   virtual bool SetCrtc(uint32_t crtc_id,
@@ skipping 89 matching lines @@
 
   // Drm master related
   virtual bool SetMaster();
   virtual bool DropMaster();
 
   int get_fd() const { return fd_; }
 
   HardwareDisplayPlaneManager* plane_manager() { return plane_manager_.get(); }
 
  protected:
-  // Responsible for late initialization of the IO thread. This needs to happen
-  // after the sandbox is up, thus the late initialization.
-  virtual void InitializeIOWatcher();
-
   // The file descriptor associated with this wrapper. All DRM operations will
   // be performed using this FD.
   // TODO(dnicoara) Make this a base::File
   int fd_;
 
   scoped_ptr<HardwareDisplayPlaneManager> plane_manager_;
 
-  // If we need to block when performing page flips this is set to true.
-  bool use_sync_flips_;
-
  private:
   class IOWatcher;
 
   // Path to DRM device.
   const char* device_path_;
 
   // Helper thread to perform IO listener operations.
-  // TODO(dnicoara) This should really be supported by the main thread.
-  // Alternatively we should have a way to access the IO thread's task runner.
-  base::Thread io_thread_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // Watcher for |fd_| listening for page flip events.
   scoped_refptr<IOWatcher> watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(DriWrapper);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRI_DRI_WRAPPER_H_