In video/ replace mock macros with unified MOCK_METHOD macro

Bug: webrtc:11564
Change-Id: Iec9dded7a3f045e048d0546c268ae206a7d3a7c7
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/175128
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31264}
diff --git a/video/call_stats2_unittest.cc b/video/call_stats2_unittest.cc
index 73fe4b4..b3d43cb 100644
--- a/video/call_stats2_unittest.cc
+++ b/video/call_stats2_unittest.cc
@@ -33,7 +33,7 @@
   MockStatsObserver() {}
   virtual ~MockStatsObserver() {}
 
-  MOCK_METHOD2(OnRttUpdate, void(int64_t, int64_t));
+  MOCK_METHOD(void, OnRttUpdate, (int64_t, int64_t), (override));
 };
 
 class CallStats2Test : public ::testing::Test {