Validate that ui::Event::time_stamp comes from the same clock as TimeTicks::Now

ui/events/cocoa/events_mac.mm

Index: ui/events/cocoa/events_mac.mm
diff --git a/ui/events/cocoa/events_mac.mm b/ui/events/cocoa/events_mac.mm
index 8b4cde2fabcb5097eee7d3877062e14f6d709490..dbfd64c7fdcd36360671423bdd98fca793366f23 100644
--- a/ui/events/cocoa/events_mac.mm
+++ b/ui/events/cocoa/events_mac.mm
@@ -84,8 +84,10 @@ base::TimeTicks EventTimeFromNative(const base::NativeEvent& native_event) {
   int64_t seconds = since_system_startup;
   since_system_startup -= seconds;
   int64_t microseconds = since_system_startup * 1000000;
-  return ui::EventTimeStampFromSeconds(seconds) +
+  base::TimeTicks timestamp = ui::EventTimeStampFromSeconds(seconds) +
          base::TimeDelta::FromMicroseconds(microseconds);
+  ValidateEventTimeClock(&timestamp);
+  return timestamp;
 }
 
 gfx::Point EventLocationFromNative(const base::NativeEvent& native_event) {