ui: Add out-of-line copy ctors for complex classes.

ui/ozone/public/overlay_candidates_ozone.cc

Index: ui/ozone/public/overlay_candidates_ozone.cc
diff --git a/ui/ozone/public/overlay_candidates_ozone.cc b/ui/ozone/public/overlay_candidates_ozone.cc
index 89777b7f843040f15422e3caa4a1bb950d703818..d6fdc009edba82d551b0dd541ddd8396b41889b7 100644
--- a/ui/ozone/public/overlay_candidates_ozone.cc
+++ b/ui/ozone/public/overlay_candidates_ozone.cc
@@ -11,6 +11,9 @@ namespace ui {
 OverlayCandidatesOzone::OverlaySurfaceCandidate::OverlaySurfaceCandidate()
     : is_clipped(false) {}
 
+OverlayCandidatesOzone::OverlaySurfaceCandidate::OverlaySurfaceCandidate(
+    const OverlaySurfaceCandidate& other) = default;
+
 OverlayCandidatesOzone::OverlaySurfaceCandidate::~OverlaySurfaceCandidate() {
 }