Background tracing: Disable when highres clock is not available

content/browser/tracing/background_tracing_manager_impl.cc

Index: content/browser/tracing/background_tracing_manager_impl.cc
diff --git a/content/browser/tracing/background_tracing_manager_impl.cc b/content/browser/tracing/background_tracing_manager_impl.cc
index 70215ba36275cd92babc9fbfb646ad4638fad115..be40081fa7558055bc1f7705e6d98f7f0daa4656 100644
--- a/content/browser/tracing/background_tracing_manager_impl.cc
+++ b/content/browser/tracing/background_tracing_manager_impl.cc
@@ -37,6 +37,7 @@ enum BackgroundTracingMetrics {
   FINALIZATION_DISALLOWED = 6,
   FINALIZATION_STARTED = 7,
   FINALIZATION_COMPLETE = 8,
+  SCENARIO_ACTION_FAILED_LOWRES_CLOCK = 9,
   NUMBER_OF_BACKGROUND_TRACING_METRICS,
 };
 
@@ -132,6 +133,13 @@ bool BackgroundTracingManagerImpl::SetActiveScenario(
   if (is_tracing_)
     return false;
 
+  // If we don't have a high resolution timer available, traces will be
+  // too inaccurate to be useful.
+  if (!base::TimeTicks::IsHighResolution()) {
+    RecordBackgroundTracingMetric(SCENARIO_ACTION_FAILED_LOWRES_CLOCK);
+    return false;
+  }
+
   bool requires_anonymized_data = (data_filtering == ANONYMIZE_DATA);
 
   // If the I/O thread isn't running, this is a startup scenario and