Add SurfaceReference class.

cc/ipc/traits_test_service.mojom

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module cc.mojom;
 
 import "cc/ipc/begin_frame_args.mojom";
 import "cc/ipc/compositor_frame.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.mojom";
 import "cc/ipc/render_pass_id.mojom";
 import "cc/ipc/returned_resource.mojom";
 import "cc/ipc/selection.mojom";
 import "cc/ipc/shared_quad_state.mojom";
 import "cc/ipc/surface_id.mojom";
+import "cc/ipc/surface_reference.mojom";
 import "cc/ipc/surface_sequence.mojom";
 import "cc/ipc/transferable_resource.mojom";
 
 // All functions on this interface echo their arguments to test StructTraits
 // serialization and deserialization.
 interface TraitsTestService {
   [Sync]
   EchoBeginFrameArgs(BeginFrameArgs b) => (BeginFrameArgs pass);
 
   [Sync]
@@ skipping 21 matching lines @@
   [Sync]
   EchoSelection(Selection s) => (Selection pass);
 
   [Sync]
   EchoSharedQuadState(SharedQuadState s) => (SharedQuadState pass);
 
   [Sync]
   EchoSurfaceId(SurfaceId s) => (SurfaceId pass);
 
   [Sync]
+  EchoSurfaceReference(SurfaceReference s) => (SurfaceReference ref);

[vmpstr, 2016/12/02 19:33:35]

What are the variable names here? The rest of the items on the rhs are "pass",
but here it's "ref" I'm sure it doesn't really matter, but I'm just curious.

[kylechar, 2016/12/02 20:16:23]

They're the variable names that get used in the autogen code. I changed the
output variable name to be "pass" too just for consistency but it doesn't make a
difference.

+
+  [Sync]
   EchoSurfaceSequence(SurfaceSequence s) => (SurfaceSequence pass);
 
   [Sync]
   EchoTransferableResource(TransferableResource t) =>
       (TransferableResource pass);
 };