Implement DrawQuad StructTraits

cc/ipc/traits_test_service.mojom

Index: cc/ipc/traits_test_service.mojom
diff --git a/cc/ipc/traits_test_service.mojom b/cc/ipc/traits_test_service.mojom
index 6ddfdfe673b72e46ea96aaf8f771ddb68e5d08d3..3005db3811f3ce737f64aec064a03c505457812b 100644
--- a/cc/ipc/traits_test_service.mojom
+++ b/cc/ipc/traits_test_service.mojom
@@ -8,6 +8,7 @@ import "cc/ipc/begin_frame_args.mojom";
 import "cc/ipc/compositor_frame_metadata.mojom";
 import "cc/ipc/filter_operation.mojom";
 import "cc/ipc/filter_operations.mojom";
+import "cc/ipc/quads.mojom";
 import "cc/ipc/render_pass_id.mojom";
 import "cc/ipc/returned_resource.mojom";
 import "cc/ipc/selection.mojom";
@@ -33,6 +34,9 @@ interface TraitsTestService {
   EchoFilterOperations(FilterOperations f) => (FilterOperations pass);
 
   [Sync]
+  EchoQuadList(QuadList q) => (QuadList pass);
+
+  [Sync]
   EchoRenderPassId(RenderPassId r) => (RenderPassId pass);
 
   [Sync]