Delete all use of tick_util.h.

webrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc

Index: webrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc
diff --git a/webrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc b/webrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc
index bdd74a491b0a8b3d8430bc029b206d500114feff..78f1e5c9640fabb47bf5953c75db8abf01ce16ee 100644
--- a/webrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc
+++ b/webrtc/modules/video_coding/utility/ivf_file_writer_unittest.cc
@@ -15,7 +15,6 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/modules/rtp_rtcp/source/byte_io.h"
-#include "webrtc/system_wrappers/include/tick_util.h"
 #include "webrtc/test/testsupport/fileutils.h"
 
 namespace webrtc {
@@ -30,7 +29,7 @@ class IvfFileWriterTest : public ::testing::Test {
  protected:
   void SetUp() override {
     const int64_t start_id =
-        reinterpret_cast<int64_t>(this) ^ TickTime::MicrosecondTimestamp();
+        reinterpret_cast<int64_t>(this) ^ rtc::TimeMicros();
     int64_t id = start_id;
     do {
       std::ostringstream oss;