Changing multiprocess test SpawnChild to return a struct.

base/files/file_locking_unittest.cc

Index: base/files/file_locking_unittest.cc
diff --git a/base/files/file_locking_unittest.cc b/base/files/file_locking_unittest.cc
index b709b7536c4ad87f9bd4984a7e2d4dbe9bb338ad..a5da65035345cff5956a3bdf05443829203bdb25 100644
--- a/base/files/file_locking_unittest.cc
+++ b/base/files/file_locking_unittest.cc
@@ -152,9 +152,10 @@ class FileLockingTest : public testing::Test {
         base::GetMultiProcessTestChildBaseCommandLine());
     child_command_line.AppendSwitchPath(kTempDirFlag, temp_path);
     child_command_line.AppendSwitch(unlock_action);
-    lock_child_ =
-        base::SpawnMultiProcessTestChild(ChildMainString, child_command_line,
-                                         base::LaunchOptions());
+
+    base::SpawnChildResult spawn_result = base::SpawnMultiProcessTestChild(
+        ChildMainString, child_command_line, base::LaunchOptions());
+    lock_child_ = std::move(spawn_result.process);
     ASSERT_TRUE(lock_child_.IsValid());
 
     // Wait for the child to lock the file.