Make stack sampling profiler sample beyond startup.

components/metrics/public/cpp/call_stack_profile_struct_traits.h

Index: components/metrics/public/cpp/call_stack_profile_struct_traits.h
diff --git a/components/metrics/public/cpp/call_stack_profile_struct_traits.h b/components/metrics/public/cpp/call_stack_profile_struct_traits.h
index ddf78d5f3c9b5139d02803ea5d8ed4e7f3844cb5..d3ccd0a3c71253171ae1a3c3075b85dc26c27730 100644
--- a/components/metrics/public/cpp/call_stack_profile_struct_traits.h
+++ b/components/metrics/public/cpp/call_stack_profile_struct_traits.h
@@ -307,6 +307,8 @@ struct EnumTraits<metrics::mojom::Trigger,
         return metrics::mojom::Trigger::JANKY_TASK;
       case metrics::CallStackProfileParams::Trigger::THREAD_HUNG:
         return metrics::mojom::Trigger::THREAD_HUNG;
+      case metrics::CallStackProfileParams::Trigger::PERIODIC_COLLECTION:
+        return metrics::mojom::Trigger::PERIODIC_COLLECTION;
     }
     NOTREACHED();
     return metrics::mojom::Trigger::UNKNOWN;
@@ -327,6 +329,9 @@ struct EnumTraits<metrics::mojom::Trigger,
       case metrics::mojom::Trigger::THREAD_HUNG:
         *out = metrics::CallStackProfileParams::Trigger::THREAD_HUNG;
         return true;
+      case metrics::mojom::Trigger::PERIODIC_COLLECTION:
+        *out = metrics::CallStackProfileParams::Trigger::PERIODIC_COLLECTION;
+        return true;
     }
     return false;
   }