Add new SampledProfile protobuf definition

components/metrics/proto/chrome_user_metrics_extension.proto

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Protocol buffer for Chrome UMA (User Metrics Analysis).
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package metrics;
 
 import "histogram_event.proto";
 import "omnibox_event.proto";
 import "profiler_event.proto";
 import "system_profile.proto";
 import "user_action_event.proto";
 import "perf_data.proto";
+import "sampled_profile.proto";
 
-// Next tag: 11
+// Next tag: 12
 message ChromeUserMetricsExtension {
   // The product (i.e. end user application) for a given UMA log.
   enum Product {
     // Google Chrome product family.
     CHROME = 0;
   }
   // The product corresponding to this log. Note: The default value is Chrome,
   // so Chrome products will not transmit this field.
   optional Product product = 10 [default = CHROME];
 
@@ skipping 16 matching lines @@
 
   // Information about the user's browser and system configuration.
   optional SystemProfileProto system_profile = 3;
 
   // This message will log one or more of the following event types:
   repeated UserActionEventProto user_action_event = 4;
   repeated OmniboxEventProto omnibox_event = 5;
   repeated HistogramEventProto histogram_event = 6;
   repeated ProfilerEventProto profiler_event = 7;
 
+  // TODO(sque): Deprecate this field and use |sampled_profile| instead.
   repeated PerfDataProto perf_data = 8;
+
+  // A list of all collected sample-based profiles since the last UMA upload.
+  repeated SampledProfile sampled_profile = 11;
 }