PerfProvider: Run a randomly selected perf command

chrome/browser/metrics/perf/perf_provider_chromeos.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_METRICS_PERF_PERF_PROVIDER_CHROMEOS_H_
 #define CHROME_BROWSER_METRICS_PERF_PERF_PROVIDER_CHROMEOS_H_
 
 #include <string>
 #include <type_traits>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
+#include "chrome/browser/metrics/perf/cpu_identity.h"
+#include "chrome/browser/metrics/perf/random_selector.h"
 #include "chrome/browser/sessions/session_restore.h"
 #include "chromeos/dbus/power_manager_client.h"
 #include "chromeos/login/login_state.h"
 #include "components/metrics/proto/sampled_profile.pb.h"
 
 namespace metrics {
 
 class WindowedIncognitoObserver;
 
 // Provides access to ChromeOS perf data. perf aka "perf events" is a
@@ skipping 162 matching lines @@
   // Collects perf data after a session restore. |time_after_restore| is how
   // long ago the session restore started. |num_tabs_restored| is the total
   // number of tabs being restored.
   void CollectPerfDataAfterSessionRestore(
       const base::TimeDelta& time_after_restore,
       int num_tabs_restored);
 
   // Parameters controlling how profiles are collected.
   CollectionParams collection_params_;
 
+  // Set of commands to choose from.
+  RandomSelector command_selector_;
+
   // Vector of SampledProfile protobufs containing perf profiles.
   std::vector<SampledProfile> cached_perf_data_;
 
   // For scheduling collection of perf data.
   base::OneShotTimer timer_;
 
   // For detecting when changes to the login state.
   LoginObserver login_observer_;
 
   // Record of the last login time.
@@ skipping 12 matching lines @@
   // obsolete callbacks.
   SessionRestore::CallbackSubscription
       on_session_restored_callback_subscription_;
 
   // To pass around the "this" pointer across threads safely.
   base::WeakPtrFactory<PerfProvider> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PerfProvider);
 };
 
+namespace internal {
+
+// Exposed for unit testing.
+
+const std::vector<RandomSelector::WeightAndValue> GetDefaultCommandsForCpu(

[Alexei Svitkine (slow), 2015/10/13 17:31:19]

Nit: No need for const on the return value

[dhsharp, 2015/10/13 23:36:22]

Done.

+    const CPUIdentity& cpuid);
+
+}  // namespace internal
+
 }  // namespace metrics
 
 #endif  // CHROME_BROWSER_METRICS_PERF_PERF_PROVIDER_CHROMEOS_H_