Revert of ozone: Wait on EGLFence before committing buffers. Avoid using GL.

ui/ozone/platform/drm/gpu/gbm_surfaceless.cc

Index: ui/ozone/platform/drm/gpu/gbm_surfaceless.cc
diff --git a/ui/ozone/platform/drm/gpu/gbm_surfaceless.cc b/ui/ozone/platform/drm/gpu/gbm_surfaceless.cc
index 722de976b72684a39248b0e149258c3f0d5b33b2..b436a7b2871433ad8d3bce905e3b7fc7252c5811 100644
--- a/ui/ozone/platform/drm/gpu/gbm_surfaceless.cc
+++ b/ui/ozone/platform/drm/gpu/gbm_surfaceless.cc
@@ -37,6 +37,8 @@
       widget_(widget),
       has_implicit_external_sync_(
           HasEGLExtension("EGL_ARM_implicit_external_sync")),
+      has_image_flush_external_(
+          HasEGLExtension("EGL_EXT_image_flush_external")),
       weak_factory_(this) {
   surface_factory_->RegisterSurface(window_->widget(), this);
   unsubmitted_frames_.push_back(base::MakeUnique<PendingFrame>());
@@ -103,6 +105,7 @@
     return;
   }
 
+  glFlush();
   unsubmitted_frames_.back()->Flush();
 
   SwapCompletionCallback surface_swap_callback = base::Bind(
@@ -114,25 +117,31 @@
 
   // TODO: the following should be replaced by a per surface flush as it gets
   // implemented in GL drivers.
-  EGLSyncKHR fence = InsertFence(has_implicit_external_sync_);
-  if (!fence) {
-    callback.Run(gfx::SwapResult::SWAP_FAILED);
-    return;
-  }
-
-  base::Closure fence_wait_task =
-      base::Bind(&WaitForFence, GetDisplay(), fence);
-
-  base::Closure fence_retired_callback = base::Bind(
-      &GbmSurfaceless::FenceRetired, weak_factory_.GetWeakPtr(), fence, frame);
-
-  base::PostTaskWithTraitsAndReply(
-      FROM_HERE,
-      base::TaskTraits()
-          .WithShutdownBehavior(
-              base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN)
-          .MayBlock(),
-      fence_wait_task, fence_retired_callback);
+  if (has_implicit_external_sync_ || has_image_flush_external_) {
+    EGLSyncKHR fence = InsertFence(has_implicit_external_sync_);
+    if (!fence) {
+      callback.Run(gfx::SwapResult::SWAP_FAILED);
+      return;
+    }
+
+    base::Closure fence_wait_task =
+        base::Bind(&WaitForFence, GetDisplay(), fence);
+
+    base::Closure fence_retired_callback =
+        base::Bind(&GbmSurfaceless::FenceRetired, weak_factory_.GetWeakPtr(),
+                   fence, frame);
+
+    base::PostTaskWithTraitsAndReply(
+        FROM_HERE, base::TaskTraits()
+                       .WithShutdownBehavior(
+                           base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN)
+                       .MayBlock(),
+        fence_wait_task, fence_retired_callback);
+    return;  // Defer frame submission until fence signals.
+  }
+
+  frame->ready = true;
+  SubmitFrame();
 }
 
 void GbmSurfaceless::PostSubBufferAsync(
@@ -204,6 +213,9 @@
       return;
     }
 
+    if (IsUniversalDisplayLinkDevice())
+      glFinish();
+
     window_->SchedulePageFlip(planes_, frame->callback);
     planes_.clear();
   }
@@ -235,4 +247,8 @@
   SubmitFrame();
 }
 
+bool GbmSurfaceless::IsUniversalDisplayLinkDevice() {
+  return planes_.empty() ? false : planes_[0].buffer->RequiresGlFinish();
+}
+
 }  // namespace ui