Mac Overlays: Allow SolidColor and Tile quads to be candidates for overlays.

cc/output/overlay_strategy_single_on_top.cc

Index: cc/output/overlay_strategy_single_on_top.cc
diff --git a/cc/output/overlay_strategy_single_on_top.cc b/cc/output/overlay_strategy_single_on_top.cc
index d08da5cd31452a8409f9f2d9f5ced28717ce25f9..1b2a2c7bdacc629b1bc236a71685d8311629ff99 100644
--- a/cc/output/overlay_strategy_single_on_top.cc
+++ b/cc/output/overlay_strategy_single_on_top.cc
@@ -23,7 +23,8 @@ bool OverlayStrategySingleOnTop::Attempt(RenderPassList* render_passes,
   QuadList& quad_list = render_passes->back()->quad_list;
   for (auto it = quad_list.begin(); it != quad_list.end(); ++it) {
     OverlayCandidate candidate;
-    if (OverlayCandidate::FromDrawQuad(*it, &candidate) &&
+    if (OverlayCandidate::IsVideoQuad(*it) &&
+        OverlayCandidate::FromDrawQuad(*it, &candidate) &&
         TryOverlay(quad_list, candidate_list, candidate, it)) {
       return true;
     }