Include absl/memory/memory.h if absl::make_unique is used

Tbr: kwiberg@webrtc.org
Bug: None
Change-Id: Iaf4533d2ce0e80b351a8a664ef8cf7ba0e5ec583
Reviewed-on: https://webrtc-review.googlesource.com/c/115746
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Yves Gerey <yvesg@google.com>
Reviewed-by: Oleh Prypin <oprypin@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26168}
diff --git a/call/rampup_tests.cc b/call/rampup_tests.cc
index 9735421..f629dbe 100644
--- a/call/rampup_tests.cc
+++ b/call/rampup_tests.cc
@@ -10,6 +10,7 @@
 
 #include "call/rampup_tests.h"
 
+#include "absl/memory/memory.h"
 #include "call/fake_network_pipe.h"
 #include "logging/rtc_event_log/output/rtc_event_log_output_file.h"
 #include "rtc_base/checks.h"