cc: make resource keep video buffer format for hardware overlay.

components/display_compositor/compositor_overlay_candidate_validator_ozone.cc

Index: components/display_compositor/compositor_overlay_candidate_validator_ozone.cc
diff --git a/components/display_compositor/compositor_overlay_candidate_validator_ozone.cc b/components/display_compositor/compositor_overlay_candidate_validator_ozone.cc
index a8f12b7e9ecb1f12e426441d471a1fe402869290..a1d1bb5e1f03c7e0805894ef23a794cce213afd9 100644
--- a/components/display_compositor/compositor_overlay_candidate_validator_ozone.cc
+++ b/components/display_compositor/compositor_overlay_candidate_validator_ozone.cc
@@ -28,18 +28,6 @@ std::unique_ptr<cc::OverlayProcessor::Strategy> MakeOverlayStrategy(
 
 }  // namespace
 
-static gfx::BufferFormat GetBufferFormat(cc::ResourceFormat overlay_format) {
-  switch (overlay_format) {
-    // TODO(dshwang): overlay video still uses RGBA_8888.
-    case cc::RGBA_8888:
-    case cc::BGRA_8888:
-      return gfx::BufferFormat::BGRA_8888;
-    default:
-      NOTREACHED();
-      return gfx::BufferFormat::BGRA_8888;
-  }
-}
-
 // |overlay_candidates| is an object used to answer questions about possible
 // overlays configuarations.
 // |strategies_string| is a comma-separated string containing all the overaly
@@ -103,7 +91,7 @@ void CompositorOverlayCandidateValidatorOzone::CheckOverlaySupport(
 
   for (size_t i = 0; i < surfaces->size(); i++) {
     ozone_surface_list.at(i).transform = surfaces->at(i).transform;
-    ozone_surface_list.at(i).format = GetBufferFormat(surfaces->at(i).format);
+    ozone_surface_list.at(i).format = surfaces->at(i).format;

[Daniele Castagna, 2017/02/08 18:59:48]

This would now pass the format even if it's not an RGB format while we used to
accept only RGBA/BGRA.
Should we validate the format somewhere?

[dshwang, 2017/02/09 00:03:54]

Yes, DrmOverlayManager::CheckOverlaySupport() checks whether the format is
supported or not.

Actually, DrmOverlayValidator::TestPageFlip() queries the plane list (with
format) is supported to drm device (by ioctl call).

Above hack was introduced when drm doesn't support RGBA format, but it's stale.

     ozone_surface_list.at(i).display_rect = surfaces->at(i).display_rect;
     ozone_surface_list.at(i).crop_rect = surfaces->at(i).uv_rect;
     ozone_surface_list.at(i).quad_rect_in_target_space =