Implement cc::FilterOperation 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 c41398cc3f6001def2d8b8b8c2454cdd86431781..d1670fe77720313e781f196b0b41001070529466 100644
--- a/cc/ipc/traits_test_service.mojom
+++ b/cc/ipc/traits_test_service.mojom
@@ -6,6 +6,7 @@ module cc.mojom;
 
 import "cc/ipc/begin_frame_args.mojom";
 import "cc/ipc/compositor_frame_metadata.mojom";
+import "cc/ipc/filter_operation.mojom";
 import "cc/ipc/render_pass_id.mojom";
 import "cc/ipc/returned_resource.mojom";
 import "cc/ipc/selection.mojom";
@@ -25,6 +26,9 @@ interface TraitsTestService {
       (CompositorFrameMetadata pass);
 
   [Sync]
+  EchoFilterOperation(FilterOperation f) => (FilterOperation pass);
+
+  [Sync]
   EchoRenderPassId(RenderPassId r) => (RenderPassId pass);
 
   [Sync]