Adding missing #include on absl/memory/memory.h.

These two files were using absl::make_unique without #including the
header that declares it.

Bug: None
Change-Id: I03019c9a7e06370631680b474d04dd33716b0fe3
Reviewed-on: https://webrtc-review.googlesource.com/c/107041
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25266}

api/BUILD.gn

@@ -560,6 +560,7 @@ if (rtc_include_tests) {
     deps = [
       ":libjingle_peerconnection_api",
       "../rtc_base:checks",
+      "../third_party/abseil-cpp/absl/memory:memory",
     ]
   }
 

api/test/fake_media_transport.h

@@ -14,6 +14,7 @@
 #include <memory>
 #include <utility>
 
+#include "absl/memory/memory.h"
 #include "api/media_transport_interface.h"
 
 namespace webrtc {

test/BUILD.gn

@@ -211,6 +211,7 @@ if (rtc_include_tests) {
       "../rtc_base:rtc_base",
       "../system_wrappers:field_trial",
       "../system_wrappers:metrics",
+      "../third_party/abseil-cpp/absl/memory:memory",
       "//testing/gtest",
 
       # TODO(bugs.webrtc.org/9792): This is needed for downstream projects on

test/test_main_lib.cc

@@ -13,6 +13,7 @@
 #include <fstream>
 #include <string>
 
+#include "absl/memory/memory.h"
 #include "rtc_base/flags.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/thread.h"