Delete all use of tick_util.h.

Depends on Chrome cl https://codereview.chromium.org/1888003002/, which was landed some time ago.

BUG=webrtc:5740
R=stefan@webrtc.org, tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1888593004 .

Cr-Commit-Position: refs/heads/master@{#12674}
diff --git a/webrtc/modules/utility/source/process_thread_impl.cc b/webrtc/modules/utility/source/process_thread_impl.cc
index 68c7ab6..4e3606c 100644
--- a/webrtc/modules/utility/source/process_thread_impl.cc
+++ b/webrtc/modules/utility/source/process_thread_impl.cc
@@ -11,9 +11,9 @@
 #include "webrtc/modules/utility/source/process_thread_impl.h"
 
 #include "webrtc/base/checks.h"
+#include "webrtc/base/timeutils.h"
 #include "webrtc/modules/include/module.h"
 #include "webrtc/system_wrappers/include/logging.h"
-#include "webrtc/system_wrappers/include/tick_util.h"
 
 namespace webrtc {
 namespace {
@@ -188,7 +188,7 @@
 }
 
 bool ProcessThreadImpl::Process() {
-  int64_t now = TickTime::MillisecondTimestamp();
+  int64_t now = rtc::TimeMillis();
   int64_t next_checkpoint = now + (1000 * 60);
 
   {
@@ -209,7 +209,7 @@
         // Use a new 'now' reference to calculate when the next callback
         // should occur.  We'll continue to use 'now' above for the baseline
         // of calculating how long we should wait, to reduce variance.
-        int64_t new_now = TickTime::MillisecondTimestamp();
+        int64_t new_now = rtc::TimeMillis();
         m.next_callback = GetNextCallbackTime(m.module, new_now);
       }
 
@@ -227,7 +227,7 @@
     }
   }
 
-  int64_t time_to_wait = next_checkpoint - TickTime::MillisecondTimestamp();
+  int64_t time_to_wait = next_checkpoint - rtc::TimeMillis();
   if (time_to_wait > 0)
     wake_up_->Wait(static_cast<unsigned long>(time_to_wait));