Use PowerSaveBlocker for audio and video on Chrome OS.

chromeos/dbus/power_policy_controller.h

 // Copyright (c) 2013 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 CHROMEOS_DBUS_POWER_POLICY_CONTROLLER_H_
 #define CHROMEOS_DBUS_POWER_POLICY_CONTROLLER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 14 matching lines @@
 
   // Returns true if the global instance has been initialized.
   static bool IsInitialized();
 
   // Destroys the global instance.
   static void Shutdown();
 
   // Returns the global instance. Initialize() must be called first.
   static PowerPolicyController* Get();
 
+  // Reasons why a wake lock may be added.
+  enum WakeLockReason {
+    REASON_AUDIO_PLAYBACK,
+    REASON_VIDEO_PLAYBACK,
+    REASON_OTHER,
+  };
+
   // Note: Do not change these values; they are used by preferences.
   enum Action {
     ACTION_SUSPEND      = 0,
     ACTION_STOP_SESSION = 1,
     ACTION_SHUT_DOWN    = 2,
     ACTION_DO_NOTHING   = 3,
   };
 
   // Values of various power-management-related preferences.
   struct PrefValues {
@@ skipping 27 matching lines @@
   // Returns a string describing |policy|.  Useful for tests.
   static std::string GetPolicyDebugString(
       const power_manager::PowerManagementPolicy& policy);
 
   // Delay in milliseconds between the screen being turned off and the screen
   // being locked. Used if the |enable_auto_screen_lock| pref is set but
   // |*_screen_lock_delay_ms| are unset or set to higher values than what this
   // constant would imply.
   static const int kScreenLockAfterOffDelayMs;
 
+  // String added to a PowerManagementPolicy |reason| field if the policy has
+  // been modified by preferences.
+  static const char kPrefsReason[];
+
   // Updates |prefs_policy_| with |values| and sends an updated policy.
   void ApplyPrefs(const PrefValues& values);
 
-  // Registers a request to temporarily prevent the screen from getting
-  // dimmed or turned off or the system from suspending in response to user
-  // inactivity and sends an updated policy.  |reason| is a human-readable
-  // description of the reason the lock was created.  Returns a unique ID
-  // that can be passed to RemoveWakeLock() later.
-  int AddScreenWakeLock(const std::string& reason);
-  int AddSystemWakeLock(const std::string& reason);
+  // Registers a request to temporarily prevent the screen from getting dimmed
+  // or turned off or the system from suspending in response to user inactivity
+  // and sends an updated policy. |description| is a human-readable description
+  // of the reason the lock was created. Returns a unique ID that can be passed
+  // to RemoveWakeLock() later.
+  int AddScreenWakeLock(WakeLockReason reason, const std::string& description);
+  int AddSystemWakeLock(WakeLockReason reason, const std::string& description);
 
   // Unregisters a request previously created via AddScreenWakeLock() or
   // AddSystemWakeLock() and sends an updated policy.
   void RemoveWakeLock(int id);
 
   // PowerManagerClient::Observer implementation:
   void PowerManagerRestarted() override;
 
  private:
   explicit PowerPolicyController(PowerManagerClient* client);
   ~PowerPolicyController() override;
 
   friend class PowerPrefsTest;
 
-  typedef std::map<int, std::string> WakeLockMap;
+  // Details about a wake lock added via AddScreenWakeLock() or
+  // AddSystemWakeLock().
+  struct WakeLock {
+    enum Type {
+      TYPE_SCREEN,
+      TYPE_SYSTEM,
+    };
+
+    WakeLock(Type type, WakeLockReason reason, const std::string& description);
+    ~WakeLock();
+
+    Type type;

[bartfab (slow), 2015/02/23 13:56:49]

Nit: const.

[Daniel Erat, 2015/02/23 16:34:05]

Done.

+    WakeLockReason reason;

[bartfab (slow), 2015/02/23 13:56:49]

Nit: const.

[Daniel Erat, 2015/02/23 16:34:05]

Done.

+    std::string description;

[bartfab (slow), 2015/02/23 13:56:49]

Nit: const.

[Daniel Erat, 2015/02/23 16:34:05]

Done.

+  };
+
+  typedef std::map<int, WakeLock> WakeLockMap;

[bartfab (slow), 2015/02/23 13:56:49]

Nit: Use C++11 using= instead of typedef.

[Daniel Erat, 2015/02/23 16:34:05]

Done.

+
+  // Helper method for AddScreenWakeLock() and AddSystemWakeLock().
+  int AddWakeLockInternal(WakeLock::Type type,
+                          WakeLockReason reason,
+                          const std::string& description);
 
   // Sends a policy based on |prefs_policy_| to the power manager.
   void SendCurrentPolicy();
 
   PowerManagerClient* client_;  // weak
 
   // Policy derived from values passed to ApplyPrefs().
   power_manager::PowerManagementPolicy prefs_policy_;
 
   // Was ApplyPrefs() called?
   bool prefs_were_set_;
 
   // Maps from an ID representing a request to prevent the screen from
   // getting dimmed or turned off or to prevent the system from suspending
-  // to the reason for the request.
-  WakeLockMap screen_wake_locks_;
-  WakeLockMap system_wake_locks_;
+  // to details about the request.
+  WakeLockMap wake_locks_;
 
-  // Should entries in |screen_wake_locks_| be honored?  If false, screen
-  // wake locks are just treated as system wake locks instead.
+  // Should TYPE_SCREEN entries in |wake_locks_| be honored?  If false, screen
+  // wake locks are just treated as TYPE_SYSTEM instead.
   bool honor_screen_wake_locks_;
 
   // Next ID to be used by AddScreenWakeLock() or AddSystemWakeLock().
   int next_wake_lock_id_;
 
   DISALLOW_COPY_AND_ASSIGN(PowerPolicyController);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_POWER_POLICY_CONTROLLER_H_