Added a TODO comment for backdrop_filter_quality in skia_renderer

Bug: N/A
Change-Id: Ia15dc301bbf8b91383b50528b006495a56b8236a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2024069
Auto-Submit: Jun Liu <yjliu@chromium.org>
Commit-Queue: weiliangc <weiliangc@chromium.org>
Reviewed-by: weiliangc <weiliangc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#736081}

components/viz/service/display/skia_renderer.cc

@@ -2317,6 +2317,7 @@ SkiaRenderer::DrawRPDQParams SkiaRenderer::CalculateRPDQParams(
   }
 
   // Convert CC image filters for the backdrop into a SkImageFilter root node
+  // TODO(weiliangc): ChromeOS would need backdrop_filter_quality implemented
   if (backdrop_filters) {
     DCHECK(!backdrop_filters->IsEmpty());