Changing multiprocess test SpawnChild to return a struct.

sandbox/mac/xpc_message_server_unittest.cc

Index: sandbox/mac/xpc_message_server_unittest.cc
diff --git a/sandbox/mac/xpc_message_server_unittest.cc b/sandbox/mac/xpc_message_server_unittest.cc
index 0feaac975e434c0a34b5993e946d671a212e99a8..336f524fc37ac70a0be7ad065a6a7d0bc507a64e 100644
--- a/sandbox/mac/xpc_message_server_unittest.cc
+++ b/sandbox/mac/xpc_message_server_unittest.cc
@@ -147,10 +147,10 @@ TEST(XPCMessageServerTest, GetSenderPID) {
 #pragma GCC diagnostic pop
   ASSERT_EQ(KERN_SUCCESS, kr);
 
-  base::Process child = base::SpawnMultiProcessTestChild(
-      "GetSenderPID",
-      base::GetMultiProcessTestChildBaseCommandLine(),
+  base::SpawnChildResult spawn_result = base::SpawnMultiProcessTestChild(
+      "GetSenderPID", base::GetMultiProcessTestChildBaseCommandLine(),
       base::LaunchOptions());
+  base::Process child = std::move(spawn_result.process);
   ASSERT_TRUE(child.IsValid());
 
   int exit_code = -1;