cros: Suspend media sessions on SuspendImminent

ash/system/power/power_event_observer.cc

Index: ash/system/power/power_event_observer.cc
diff --git a/ash/system/power/power_event_observer.cc b/ash/system/power/power_event_observer.cc
index 9a773a66f1e3867c4a58762f214e88de05d753d9..f1e19043869bfe628dfe81c3f837f31a9a9de892 100644
--- a/ash/system/power/power_event_observer.cc
+++ b/ash/system/power/power_event_observer.cc
@@ -7,6 +7,7 @@
 #include "ash/public/cpp/config.h"
 #include "ash/session/session_controller.h"
 #include "ash/shell.h"
+#include "ash/shell_delegate.h"
 #include "ash/shell_port.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "ash/wm/power_button_controller.h"
@@ -44,8 +45,7 @@ void OnSuspendDisplaysCompleted(const base::Closure& suspend_callback,
 
 }  // namespace
 
-PowerEventObserver::PowerEventObserver()
-    : screen_locked_(false), waiting_for_lock_screen_animations_(false) {
+PowerEventObserver::PowerEventObserver() {
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(
       this);
   chromeos::DBusThreadManager::Get()->GetSessionManagerClient()->AddObserver(
@@ -102,8 +102,8 @@ void PowerEventObserver::SuspendImminent() {
         ->GetSessionManagerClient()
         ->RequestLockScreen();
   } else if (waiting_for_lock_screen_animations_) {
-    // The lock-before-suspending pref has been set and the lock screen is ready
-    // but the animations have not completed yet.  This can happen if a suspend
+    // The auto-screen-lock pref has been set and the lock screen is ready but
+    // the animations have not completed yet.  This can happen if a suspend
     // request is canceled after the lock screen is ready but before the
     // animations have completed and then another suspend request is immediately
     // started.  In practice, it is highly unlikely that this will ever happen
@@ -113,7 +113,7 @@ void PowerEventObserver::SuspendImminent() {
                                 ->GetPowerManagerClient()
                                 ->GetSuspendReadinessCallback();
   } else {
-    // The lock-before-suspending pref is not set or the screen has already been
+    // The auto-screen-lock pref is not set or the screen has already been
     // locked and the animations have completed.  Rendering can be stopped now.
     StopRenderingRequests();
   }
@@ -153,6 +153,7 @@ void PowerEventObserver::ScreenIsLocked() {
   // The screen is now locked but the pending suspend, if any, will be blocked
   // until all the animations have completed.
   if (!screen_lock_callback_.is_null()) {
+    Shell::Get()->shell_delegate()->SuspendMediaSessions();
     VLOG(1) << "Screen locked due to suspend";
   } else {
     VLOG(1) << "Screen locked without suspend";