ozone: dri: add synchronous SwapBuffers support on surfaceless

ui/ozone/platform/dri/hardware_display_controller.h

Index: ui/ozone/platform/dri/hardware_display_controller.h
diff --git a/ui/ozone/platform/dri/hardware_display_controller.h b/ui/ozone/platform/dri/hardware_display_controller.h
index e2db520ed8538c42096ebb49a4e783dabc8d5b26..f576cb3dca49b6233726545825207b014ffc323b 100644
--- a/ui/ozone/platform/dri/hardware_display_controller.h
+++ b/ui/ozone/platform/dri/hardware_display_controller.h
@@ -123,7 +123,7 @@ class OZONE_EXPORT HardwareDisplayController
   // called again before the page flip occurrs.
   //
   // Returns true if the page flip was successfully registered, false otherwise.
-  bool SchedulePageFlip(const base::Closure& callback);
+  bool SchedulePageFlip(bool is_sync, const base::Closure& callback);
 
   // Set the hardware cursor to show the contents of |surface|.
   bool SetCursor(const scoped_refptr<ScanoutBuffer>& buffer);
@@ -158,7 +158,7 @@ class OZONE_EXPORT HardwareDisplayController
   // 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();
 
@@ -169,10 +169,12 @@ class OZONE_EXPORT HardwareDisplayController
 
   struct PageFlipRequest {
     PageFlipRequest(const OverlayPlaneList& planes,
+                    bool is_sync,
                     const base::Closure& callback);
     ~PageFlipRequest();
 
     OverlayPlaneList planes;
+    bool is_sync;
     base::Closure callback;
   };