Sort #includes that got unsorted when gmock.h and gtest.h moved to webrtc/test/

gmock.h and gtest.h were moved (or rather, got wrappers so that we
could put some icky compatibility hacks in one place instead of 500)
in this CL: https://codereview.webrtc.org/2358993004/

NOPRESUBMIT=true
BUG=webrtc:6398

Review-Url: https://codereview.webrtc.org/2381013002
Cr-Commit-Position: refs/heads/master@{#14464}
diff --git a/webrtc/modules/video_coding/frame_buffer2_unittest.cc b/webrtc/modules/video_coding/frame_buffer2_unittest.cc
index 1397aeb..7f8ac67 100644
--- a/webrtc/modules/video_coding/frame_buffer2_unittest.cc
+++ b/webrtc/modules/video_coding/frame_buffer2_unittest.cc
@@ -15,8 +15,6 @@
 #include <limits>
 #include <vector>
 
-#include "webrtc/test/gmock.h"
-#include "webrtc/test/gtest.h"
 #include "webrtc/base/platform_thread.h"
 #include "webrtc/base/random.h"
 #include "webrtc/modules/video_coding/frame_object.h"
@@ -24,6 +22,8 @@
 #include "webrtc/modules/video_coding/sequence_number_util.h"
 #include "webrtc/modules/video_coding/timing.h"
 #include "webrtc/system_wrappers/include/clock.h"
+#include "webrtc/test/gmock.h"
+#include "webrtc/test/gtest.h"
 
 namespace webrtc {
 namespace video_coding {