Compute damage rect for Cast video compositing

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 3c0cfb12c230fd6fedb1cd2bf797edbac8968a16..b87c9c325bca5af6eea921524d7f2f489830e021 100644
--- a/components/display_compositor/compositor_overlay_candidate_validator_ozone.cc
+++ b/components/display_compositor/compositor_overlay_candidate_validator_ozone.cc
@@ -9,6 +9,7 @@
 #include <utility>
 
 #include "base/memory/ptr_util.h"
+#include "cc/output/overlay_strategy_cast_underlay.h"
 #include "cc/output/overlay_strategy_fullscreen.h"
 #include "cc/output/overlay_strategy_single_on_top.h"
 #include "cc/output/overlay_strategy_underlay.h"
@@ -31,9 +32,11 @@ static gfx::BufferFormat GetBufferFormat(cc::ResourceFormat overlay_format) {
 CompositorOverlayCandidateValidatorOzone::
     CompositorOverlayCandidateValidatorOzone(
         std::unique_ptr<ui::OverlayCandidatesOzone> overlay_candidates,
-        bool single_fullscreen)
+        bool single_fullscreen,
+        bool cast_underlay)
     : overlay_candidates_(std::move(overlay_candidates)),
       single_fullscreen_(single_fullscreen),
+      cast_underlay_(cast_underlay),
       software_mirror_active_(false) {}
 
 CompositorOverlayCandidateValidatorOzone::
@@ -44,6 +47,9 @@ void CompositorOverlayCandidateValidatorOzone::GetStrategies(
   if (single_fullscreen_) {
     strategies->push_back(
         base::MakeUnique<cc::OverlayStrategyFullscreen>(this));
+  } else if (cast_underlay_) {
+    strategies->push_back(
+        base::MakeUnique<cc::OverlayStrategyCastUnderlay>(this));
   } else {
     strategies->push_back(
         base::MakeUnique<cc::OverlayStrategySingleOnTop>(this));