Metrics provider for statistical stack profiler

components/metrics/proto/sampled_profile.proto

Index: components/metrics/proto/sampled_profile.proto
diff --git a/components/metrics/proto/sampled_profile.proto b/components/metrics/proto/sampled_profile.proto
index 1b8d66ff44fe6f083b8486d8826a37e304ca0d37..5725309eab32085238edcfb4bb2a80828cf64a99 100644
--- a/components/metrics/proto/sampled_profile.proto
+++ b/components/metrics/proto/sampled_profile.proto
@@ -8,12 +8,13 @@ option optimize_for = LITE_RUNTIME;
 
 package metrics;
 
+import "call_stack_profile.proto";
 import "perf_data.proto";
 
 // Protocol buffer for collected sample-based profiling data.
 // Contains the parameters and data from a single profile collection event.
 
-// Next tag: 9
+// Next tag: 10
 message SampledProfile {
   // Indicates the event that triggered this collection.
   enum TriggerEvent {
@@ -59,6 +60,9 @@ message SampledProfile {
   // collected. Only set when |trigger_event| is RESTORE_SESSION.
   optional int64 ms_after_restore = 8;
 
-  // The actual perf data that was collected.
+  // Sampled profile data collected from Linux perf tool.
   optional PerfDataProto perf_data = 4;
+
+  // Sampled profile data collected by periodic sampling of call stacks.
+  optional CallStackProfile call_stack_profile = 9;
 }