Changing multiprocess test SpawnChild to return a struct.

base/debug/stack_trace_unittest.cc

Index: base/debug/stack_trace_unittest.cc
diff --git a/base/debug/stack_trace_unittest.cc b/base/debug/stack_trace_unittest.cc
index 560dc1ddde8dc5ee7dd42e62b0e0e296ad5a5ac4..838af54fcd94d2ff5b2bf15bf3fd22cf954636af 100644
--- a/base/debug/stack_trace_unittest.cc
+++ b/base/debug/stack_trace_unittest.cc
@@ -171,7 +171,8 @@ MULTIPROCESS_TEST_MAIN(MismatchedMallocChildProcess) {
 // and e.g. mismatched new[]/delete would cause a hang because
 // of re-entering malloc.
 TEST_F(StackTraceTest, AsyncSignalUnsafeSignalHandlerHang) {
-  Process child = SpawnChild("MismatchedMallocChildProcess");
+  SpawnChildResult spawn_result = SpawnChild("MismatchedMallocChildProcess");
+  Process child = std::move(spawn_result.process);

[dcheng, 2017/03/08 22:53:44]

Strictly speaking, this seems unnecessary, we could just use the value in the
struct as-is, right?

[Jay Civelli, 2017/03/14 16:29:12]

Now using the struct directly.

   ASSERT_TRUE(child.IsValid());
   int exit_code;
   ASSERT_TRUE(child.WaitForExitWithTimeout(TestTimeouts::action_timeout(),