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-Original-Commit-Position: refs/heads/master@{#14464}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: ac9f876bc06b8152ecc3a328147cdab19136361b
diff --git a/video/stats_counter_unittest.cc b/video/stats_counter_unittest.cc
index b906532..e04b47f 100644
--- a/video/stats_counter_unittest.cc
+++ b/video/stats_counter_unittest.cc
@@ -10,9 +10,8 @@
 
 #include "webrtc/video/stats_counter.h"
 
-#include "webrtc/test/gtest.h"
-
 #include "webrtc/system_wrappers/include/clock.h"
+#include "webrtc/test/gtest.h"
 
 namespace webrtc {
 namespace {