Make stack sampling profiler sample beyond startup.

components/metrics/call_stack_profile_collector.cc

Index: components/metrics/call_stack_profile_collector.cc
diff --git a/components/metrics/call_stack_profile_collector.cc b/components/metrics/call_stack_profile_collector.cc
index 4cdd9ec83485819cc4959c75c2f7faf2c58fa987..a4c330acbf6ae70f08cc169e8e7780adae3ed32e 100644
--- a/components/metrics/call_stack_profile_collector.cc
+++ b/components/metrics/call_stack_profile_collector.cc
@@ -36,8 +36,10 @@ void CallStackProfileCollector::Collect(
   if (params.process != expected_process_)
     return;
 
+  CallStackProfileParams params_copy = params;
+  params_copy.start_timestamp = start_timestamp;
   CallStackProfileMetricsProvider::ReceiveCompletedProfiles(
-      params, start_timestamp, std::move(profiles));
+      &params_copy, std::move(profiles));
 }
 
 }  // namespace metrics