Add process lifetime annotations to stack samples.

components/metrics/public/interfaces/call_stack_profile_collector.mojom

Index: components/metrics/public/interfaces/call_stack_profile_collector.mojom
diff --git a/components/metrics/public/interfaces/call_stack_profile_collector.mojom b/components/metrics/public/interfaces/call_stack_profile_collector.mojom
index 6c8f04216c63b74c5a327ceee279a304335b49f2..2b5a763a4508927623f701fbe7db2c1de5d8d3d3 100644
--- a/components/metrics/public/interfaces/call_stack_profile_collector.mojom
+++ b/components/metrics/public/interfaces/call_stack_profile_collector.mojom
@@ -19,9 +19,15 @@ struct CallStackFrame {
   uint64 module_index;
 };
 
+struct CallStackSample {
+  array<CallStackFrame> frames;
+  uint32 process_phases;
+  uint32 current_activities;
+};
+
 struct CallStackProfile {
   array<CallStackModule> modules;
-  array<array<CallStackFrame>> samples;
+  array<CallStackSample> samples;
   mojo.common.mojom.TimeDelta profile_duration;
   mojo.common.mojom.TimeDelta sampling_period;
 };