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

ui/events/base_event_utils.h

Index: ui/events/base_event_utils.h
diff --git a/ui/events/base_event_utils.h b/ui/events/base_event_utils.h
index 74902516029ee8af5503075414fb485aa68b18d8..4e177803e275aea00a05aca6df8f4a40a8ad1c80 100644
--- a/ui/events/base_event_utils.h
+++ b/ui/events/base_event_utils.h
@@ -5,8 +5,10 @@
 #ifndef UI_EVENTS_BASE_EVENT_UTILS_H_
 #define UI_EVENTS_BASE_EVENT_UTILS_H_
 
+#include <memory>
 #include <stdint.h>
 
+#include "base/time/tick_clock.h"
 #include "ui/events/events_base_export.h"
 
 namespace base {
@@ -22,6 +24,12 @@ EVENTS_BASE_EXPORT uint32_t GetNextTouchEventId();
 // Checks if |flags| contains system key modifiers.
 EVENTS_BASE_EXPORT bool IsSystemKeyModifier(int flags);
 
+// Create a timestamp based on the current time.
+EVENTS_BASE_EXPORT base::TimeTicks EventTimeForNow();
+
+EVENTS_BASE_EXPORT void SetEventTickClockForTesting(
+    std::unique_ptr<base::TickClock> tick_clock);
+
 // Converts an event timestamp ticks to seconds (floating point representation).
 // WARNING: This should only be used when interfacing with platform code that
 // does not use base::Time* types.