metrics: Add dbus interface for GetRandomPerfOutput

chrome/browser/metrics/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_PROVIDER_CHROMEOS_H_
 #define CHROME_BROWSER_METRICS_PERF_PROVIDER_CHROMEOS_H_
 
 #include <string>
 #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/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
 // performance profiling infrastructure built into the linux kernel. For more
 // information, see: https://perf.wiki.kernel.org/index.php/Main_Page.
 class PerfProvider : public base::NonThreadSafe,
                      public chromeos::PowerManagerClient::Observer {
  public:
+  // Interface for detecting that an incognito window was opened.
+  class IncognitoObserverInterface {

[Ilya Sherman, 2015/07/01 03:09:02]

nit: If you really need this class, please omit the "Interface" part of the
name.  I'd prefer, though, that you simply extracted the
WindowedIncognitoObserver class to a separate file, and marked the appropriate
method as virtual if need be.

[Simon Que, 2015/07/01 20:22:57]

Done.

+   public:
+    virtual ~IncognitoObserverInterface() {}
+
+    // Returns true if an incognito window was opened during the lifetime of the
+    // object.
+    virtual bool incognito_launched() const = 0;

[Ilya Sherman, 2015/07/01 03:09:02]

nit: virtual functions are never trivial/inline-able, so please name this using
TitleCase.

[Simon Que, 2015/07/01 20:22:57]

Done.

+  };
+
   PerfProvider();
   ~PerfProvider() override;
 
   // Stores collected perf data protobufs in |sampled_profiles|. Clears all the
   // stored profile data. Returns true if it wrote to |sampled_profiles|.
   bool GetSampledProfiles(std::vector<SampledProfile>* sampled_profiles);
 
  private:
+  // For unit testing.
+  friend class PerfProviderTest;

[Ilya Sherman, 2015/07/01 03:09:02]

Please don't friend test classes -- it allows tests to muck arbitrarily with
internal state.  Instead, please expose only the necessary internal state via
protected methods, which you expose or override in a test-specific subclass.

[Simon Que, 2015/07/01 21:08:02]

Done.

+
   // Class that listens for changes to the login state. When a normal user logs
   // in, it updates PerfProvider to start collecting data.
   class LoginObserver : public chromeos::LoginState::Observer {
    public:
     explicit LoginObserver(PerfProvider* perf_provider);
 
     // Called when either the login state or the logged in user type changes.
     // Activates |perf_provider_| to start collecting.
     void LoggedInStateChanged() override;
 
@@ skipping 38 matching lines @@
   void CollectPerfDataAfterResume(const base::TimeDelta& sleep_duration,
                                   const base::TimeDelta& time_after_resume);
 
   // 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);
 
-  // Parses a perf data protobuf from the |data| passed in only if the
-  // |incognito_observer| indicates that no incognito window had been opened
-  // during the profile collection period.
+  // Parses a PerfDataProto from serialized data |perf_data|, if it exists.
+  // Parses a PerfStatProto from serialized data |perf_stat|, if it exists.
+  // Only one of these may contain data. If both |perf_data| and |perf_stat|
+  // contain data, it is counted as an error and neither is parsed.
+  // |incognito_observer| indicates whether an incognito window had been opened
+  // during the profile collection period. If there was an incognito window,
+  // discard the incoming data.
   // |trigger_event| is the cause of the perf data collection.
-  void ParseProtoIfValid(
-      scoped_ptr<WindowedIncognitoObserver> incognito_observer,
+  // |result| is the return value of running perf/quipper. It is 0 if successful
+  // and nonzero if not successful.
+  void ParseOutputProtoIfValid(
+      scoped_ptr<IncognitoObserverInterface> incognito_observer,
       scoped_ptr<SampledProfile> sampled_profile,
-      const std::vector<uint8>& data);
+      int result,
+      const std::vector<uint8>& perf_data,
+      const std::vector<uint8>& perf_stat);
 
   // Vector of SampledProfile protobufs containing perf profiles.
   std::vector<SampledProfile> cached_perf_data_;
 
   // For scheduling collection of perf data.
   base::OneShotTimer<PerfProvider> timer_;
 
   // For detecting when changes to the login state.
   LoginObserver login_observer_;
 
@@ skipping 16 matching lines @@
 
   // To pass around the "this" pointer across threads safely.
   base::WeakPtrFactory<PerfProvider> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PerfProvider);
 };
 
 }  // namespace metrics
 
 #endif  // CHROME_BROWSER_METRICS_PERF_PROVIDER_CHROMEOS_H_