Assert event timestamp to be monotonic and not from future

content/shell/renderer/layout_test/blink_test_runner.cc

Index: content/shell/renderer/layout_test/blink_test_runner.cc
diff --git a/content/shell/renderer/layout_test/blink_test_runner.cc b/content/shell/renderer/layout_test/blink_test_runner.cc
index 8cec34121dc3361bb05606c094d5da622c79c334..d7d8a430ffde358ca9831c5c1fed393beb5b5f40 100644
--- a/content/shell/renderer/layout_test/blink_test_runner.cc
+++ b/content/shell/renderer/layout_test/blink_test_runner.cc
@@ -721,6 +721,19 @@ void BlinkTestRunner::RunIdleTasks(const base::Closure& callback) {
     SchedulerRunIdleTasks(callback);
 }
 
+base::Callback<double()> BlinkTestRunner::time_function_;
+
+void BlinkTestRunner::SetMockMonotonicTimeFunction(
+    const base::Callback<double()>& time_function) const {
+  time_function_ = time_function;
+  // TODO(majidvp): Perhaps we need a generic utility to convert a
+  // base::Callback to a WTF::Function similar to WebFunction but in reverse
+  // direction.
+  WebTestingSupport::setMonotonicallyIncreasingTimeFunctionForTesting(
+    time_function_.is_null() ? nullptr : returnMockTime);
+
+}
+
 bool BlinkTestRunner::AddMediaStreamVideoSourceAndTrack(
     blink::WebMediaStream* stream) {
   DCHECK(stream);