SkiaOutputSurfaceImpl: fix sync token problem for drawing overlay render passes on macOS

Bug: 1135727
Change-Id: I92ec9961066d4d27f12f4a5d9cd92e27d7e00e8d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485633
Commit-Queue: Peng Huang <penghuang@chromium.org>
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818531}

components/viz/service/display_embedder/skia_output_surface_impl.cc

@@ -534,7 +534,6 @@ SkCanvas* SkiaOutputSurfaceImpl::BeginPaintRenderPassOverlay(
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   // Make sure there is no unsubmitted PaintFrame or PaintRenderPass.
   DCHECK(!current_paint_);
-  DCHECK(resource_sync_tokens_.empty());
 
   SkSurfaceCharacterization characterization = CreateSkSurfaceCharacterization(
       size, BufferFormat(format), mipmap, std::move(color_space),
@@ -719,6 +718,11 @@ void SkiaOutputSurfaceImpl::ScheduleOverlays(
                                    [](const CALayerOverlay& overlay) {
                                      return !!overlay.ddl;
                                    }) != overlays.end();
+  // Append |resource_sync_tokens_| which are depended by drawing render passes
+  // to overlay backings.
+  std::move(resource_sync_tokens_.begin(), resource_sync_tokens_.end(),
+            std::back_inserter(sync_tokens));
+  resource_sync_tokens_.clear();
 #else
   bool make_current = false;
 #endif