ozone: dri: add synchronous SwapBuffers support on surfaceless

ui/ozone/platform/dri/hardware_display_controller.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_HARDWARE_DISPLAY_CONTROLLER_H_
 #define UI_OZONE_PLATFORM_DRI_HARDWARE_DISPLAY_CONTROLLER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <xf86drmMode.h>
@@ skipping 107 matching lines @@
   // should not be modified in any way as it would cause screen tearing if the
   // hardware performed the flip. Note that the frontbuffer should also not
   // be modified as it could still be displayed.
   //
   // Note that this function does not block. Also, this function should not be
   // called again before the page flip occurrs.
   //
   // Returns true if the page flip was successfully registered, false otherwise.
   bool SchedulePageFlip(const base::Closure& callback);
 
+  // Like |SchedulePageFlip| but synchronous.
+  bool PageFlip();
+
   // Set the hardware cursor to show the contents of |surface|.
   bool SetCursor(const scoped_refptr<ScanoutBuffer>& buffer);
 
   bool UnsetCursor();
 
   // Moves the hardware cursor to |location|.
   bool MoveCursor(const gfx::Point& location);
 
   void AddCrtc(scoped_ptr<CrtcController> controller);
   scoped_ptr<CrtcController> RemoveCrtc(const scoped_refptr<DriWrapper>& drm,
@@ skipping 13 matching lines @@
   const std::vector<CrtcController*>& crtc_controllers() const {
     return crtc_controllers_.get();
   }
 
   scoped_refptr<DriWrapper> GetAllocationDriWrapper() const;
 
  private:
   // Returns true if any of the CRTCs is waiting for a page flip.
   bool HasPendingPageFlips() const;
 
-  bool ActualSchedulePageFlip();
+  bool ActualSchedulePageFlip(bool is_sync);
 
   void ProcessPageFlipRequest();
 
   void ClearPendingRequests();
 
   // PageFlipObserver:
   void OnPageFlipEvent() override;
 
   struct PageFlipRequest {
     PageFlipRequest(const OverlayPlaneList& planes,
@@ skipping 25 matching lines @@
   drmModeModeInfo mode_;
 
   bool is_disabled_;
 
   DISALLOW_COPY_AND_ASSIGN(HardwareDisplayController);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRI_HARDWARE_DISPLAY_CONTROLLER_H_