Fix black background when locking with fullscreen window:

ash/wm/session_state_controller_impl2.h

Index: ash/wm/session_state_controller_impl2.h
diff --git a/ash/wm/session_state_controller_impl2.h b/ash/wm/session_state_controller_impl2.h
index d5546795db2a2a002459a3c368d5b6ff9613a713..4c072087caa375af80ab6544671d319ec5f41299 100644
--- a/ash/wm/session_state_controller_impl2.h
+++ b/ash/wm/session_state_controller_impl2.h
@@ -32,6 +32,28 @@ class SessionStateControllerImpl2Test;
 
 // Displays onscreen animations and locks or suspends the system in response to
 // the power button being pressed or released.
+// Lock workflow:
+// Entry points:
+//  * StartLockAnimation (bool shutdown after lock) - starts lock that can be
+//    cancelled.
+//  * StartLockAnimationAndLockImmediately - starts uninterruptible lock
+//    animation.
+// This leads to call of either StartImmediatePreLockAnimation or
+// StartCancellablePreLockAnimation. Once they complete
+// PreLockAnimationFinished is called, and system lock is requested.
+// Once system locks and lock UI is created, OnLockStateChanged is called, and
+// StartPostLockAnimation is called. In PostLockAnimationFinished two
+// things happen : EVENT_LOCK_ANIMATION_FINISHED notification is sent (it
+// triggers third part of animation within lock UI), and check for continuing to
+// shutdown is made.
+//
+// Unlock workflow:
+// WebUI does first part of animation, and calls OnLockScreenHide(callback) that
+// triggers StartUnlockAnimationBeforeUIDestroyed(callback). Once callback is
+// called at the end of the animation, lock UI is deleted, system unlocks, and
+// OnLockStateChanged is called. It leads to
+// StartUnlockAnimationAfterUIDestroyed.
+
 class ASH_EXPORT SessionStateControllerImpl2 : public SessionStateController {
  public:
 
@@ -42,9 +64,6 @@ class ASH_EXPORT SessionStateControllerImpl2 : public SessionStateController {
 
     virtual ~TestApi();
 
-    bool lock_timer_is_running() const {
-      return controller_->lock_timer_.IsRunning();
-    }
     bool lock_fail_timer_is_running() const {
       return controller_->lock_fail_timer_.IsRunning();
     }
@@ -57,11 +76,13 @@ class ASH_EXPORT SessionStateControllerImpl2 : public SessionStateController {
     bool real_shutdown_timer_is_running() const {
       return controller_->real_shutdown_timer_.IsRunning();
     }
-
-    void trigger_lock_timeout() {
-      controller_->OnLockTimeout();
-      controller_->lock_timer_.Stop();
+    bool is_animating_lock() const {
+      return controller_->animating_lock_;
+    }
+    bool is_lock_cancellable() const {
+      return controller_->CanCancelLockAnimation();
     }
+
     void trigger_lock_fail_timeout() {
       controller_->OnLockFailTimeout();
       controller_->lock_fail_timer_.Stop();
@@ -121,13 +142,11 @@ class ASH_EXPORT SessionStateControllerImpl2 : public SessionStateController {
   friend class test::SessionStateControllerImpl2Test;
 
  private:
-  void RequestShutdownImpl();
-
-  // Starts lock timer.
-  void StartLockTimer();
+  struct UnlockedStateProperties {
+    bool background_is_hidden;
+  };
 
-  // Requests that the screen be locked and starts |lock_fail_timer_|.
-  void OnLockTimeout();
+  void RequestShutdownImpl();
 
   // Reverts the pre-lock animation, reports the error.
   void OnLockFailTimeout();
@@ -145,14 +164,52 @@ class ASH_EXPORT SessionStateControllerImpl2 : public SessionStateController {
   void OnPreShutdownAnimationTimeout();
 
   // Starts timer for final shutdown animation.
-  void StartRealShutdownTimer();
+  // If |with_animation_time| is true, it will also include time of "fade to
+  // white" shutdown animation.
+  void StartRealShutdownTimer(bool with_animation_time);
 
   // Requests that the machine be shut down.
   void OnRealShutdownTimeout();
 
+  // Starts shutdown animation that can be cancelled and starts pre-shutdown
+  // timer.
+  void StartCancellableShutdownAnimation();
+
+  // Starts non-cancellable animation and starts real shutdown timer that
+  // includes animation time.
+  void StartShutdownAnimationImpl();
+
   // Triggers late animations on the lock screen.
   void OnLockScreenAnimationFinished();
 
+  void StartImmediatePreLockAnimation();
+  void StartCancellablePreLockAnimation();
+  void CancelPreLockAnimation();
+  void StartPostLockAnimation();
+  // This method calls |callback| when animation completes.
+  void StartUnlockAnimationBeforeUIDestroyed(base::Closure &callback);
+  void StartUnlockAnimationAfterUIDestroyed();
+
+  // These methods are called when corresponding animation completes.
+  void LockAnimationCancelled();
+  void PreLockAnimationFinished();
+  void PostLockAnimationFinished();
+  void UnlockAnimationAfterUIDestroyedFinished();
+
+  // Stores properties of UI that have to be temporarily modified while locking.
+  void StoreUnlockedProperties();
+  void RestoreUnlockedProperties();
+
+  // Fades in background layer with |speed| if it was hidden in unlocked state.
+  void AnimateBackgroundAppearanceIfNecessary(
+      ash::internal::SessionStateAnimator::AnimationSpeed speed,
+      ui::LayerAnimationObserver* observer);
+
+  // Fades out background layer with |speed| if it was hidden in unlocked state.
+  void AnimateBackgroundHidingIfNecessary(
+      ash::internal::SessionStateAnimator::AnimationSpeed speed,
+      ui::LayerAnimationObserver* observer);
+
   // The current login status, or original login status from before we locked.
   user::LoginStatus login_status_;
 
@@ -166,10 +223,13 @@ class ASH_EXPORT SessionStateControllerImpl2 : public SessionStateController {
   // locking.
   bool shutdown_after_lock_;
 
-  // Started when the user first presses the power button while in a
-  // logged-in-as-a-non-guest-user, unlocked state.  When it fires, we lock the
-  // screen.
-  base::OneShotTimer<SessionStateControllerImpl2> lock_timer_;
+  // Indicates that controller displays lock animation.
+  bool animating_lock_;
+
+  // Indicates that lock animation can be undone.
+  bool can_cancel_lock_animation_;
+
+  scoped_ptr<UnlockedStateProperties> unlocked_properties_;
 
   // Started when we request that the screen be locked.  When it fires, we
   // assume that our request got dropped.