Tentative fix for a Chrome crash bug.

According to Chrome crashes, |GetDelegate().GetPageInputTiming().total_input_delay| can be |std::numeric_limits<int64_t>::min()|. I still have not figured out why this value can be negative. But I think this CL can fix the chrome crash.

Change-Id: I8709239a9d96d240840f42a4b4ab661738651a53
Bug: 1105665
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351379Reviewed-by: Hongbo Song <hbsong@google.com>
Reviewed-by: Steve Kobes <skobes@chromium.org>
Commit-Queue: Hongbo Song <hbsong@google.com>
Cr-Commit-Position: refs/heads/master@{#798155}

chrome/browser/page_load_metrics/observers/foreground_duration_ukm_observer.cc

@@ -88,6 +88,10 @@ void ForegroundDurationUKMObserver::RecordUkmIfInForeground(
 
 void ForegroundDurationUKMObserver::RecordInputTimingMetrics(
     ukm::builders::PageForegroundSession* ukm_builder) {
+  // TODO(hbsong): crbug.com/1105665
+  if (GetDelegate().GetPageInputTiming().total_input_delay.InMilliseconds() < 0)
+    return;
+
   ukm_builder
       ->SetForegroundNumInputEvents(
           GetDelegate().GetPageInputTiming().num_input_events -
@@ -101,4 +105,4 @@ void ForegroundDurationUKMObserver::RecordInputTimingMetrics(
            last_page_input_timing_.total_adjusted_input_delay)
               .InMilliseconds());
   last_page_input_timing_ = GetDelegate().GetPageInputTiming();
-}
+}
\ No newline at end of file