Fix Chromium compile.

Fixes error: invalid operands to binary expression ('std::ostream'
(aka 'basic_ostream<char>') and 'const char[19]') << "pthread_setname_np";

in test/scoped_set_thread_name_posix.cc

Change-Id: I77eeeee9c828d563aaa15331733001e522a04642
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3714964
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
diff --git a/test/scoped_set_thread_name_posix.cc b/test/scoped_set_thread_name_posix.cc
index 4720bc0..92c61bb 100644
--- a/test/scoped_set_thread_name_posix.cc
+++ b/test/scoped_set_thread_name_posix.cc
@@ -17,6 +17,7 @@
 #include <errno.h>
 #include <pthread.h>
 
+#include <ostream>
 #include <string>
 
 #include "base/check.h"