Fix a leak in wm::AnimateOnChildWindowVisibilityChanged().

RotateHidingWindowAnimationObserver is leaking from
wm::AnimateOnChildWindowVisibilityChanged() because it's not observing
animation events. The fix is to make RotateHidingWindowAnimationObserver
observe the animation events.

BUG=389296
TEST=wm_unittests:WindowAnimationsTest.RotateHideNoLeak

Review URL: https://codereview.chromium.org/343753007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283970 0039d316-1c4b-4281-b951-d872f2087c98

ui/wm/core/window_animations.cc

@@ -58,7 +58,8 @@ const float kWindowAnimation_Vertical_TranslateY = 15.f;
 // The subclass will determine when the animation is completed.
 class HidingWindowAnimationObserverBase : public aura::WindowObserver {
  public:
-  HidingWindowAnimationObserverBase(aura::Window* window) : window_(window) {
+  explicit HidingWindowAnimationObserverBase(aura::Window* window)
+      : window_(window) {
     window_->AddObserver(this);
   }
   virtual ~HidingWindowAnimationObserverBase() {
@@ -396,31 +397,29 @@ class RotateHidingWindowAnimationObserver
     : public HidingWindowAnimationObserverBase,
       public ui::LayerAnimationObserver {
  public:
-  RotateHidingWindowAnimationObserver(aura::Window* window)
-      : HidingWindowAnimationObserverBase(window), last_sequence_(NULL) {}
+  explicit RotateHidingWindowAnimationObserver(aura::Window* window)
+      : HidingWindowAnimationObserverBase(window) {}
   virtual ~RotateHidingWindowAnimationObserver() {}
 
-  void set_last_sequence(ui::LayerAnimationSequence* last_sequence) {
-    last_sequence_ = last_sequence;
+  // Destroys itself after |last_sequence| ends or is aborted. Does not take
+  // ownership of |last_sequence|, which should not be NULL.
+  void SetLastSequence(ui::LayerAnimationSequence* last_sequence) {
+    last_sequence->AddObserver(this);
   }
 
   // ui::LayerAnimationObserver:
   virtual void OnLayerAnimationEnded(
       ui::LayerAnimationSequence* sequence) OVERRIDE {
-    if (last_sequence_ == sequence)
-      OnAnimationCompleted();
+    OnAnimationCompleted();
   }
   virtual void OnLayerAnimationAborted(
       ui::LayerAnimationSequence* sequence) OVERRIDE {
-    if (last_sequence_ == sequence)
-      OnAnimationCompleted();
+    OnAnimationCompleted();
   }
   virtual void OnLayerAnimationScheduled(
       ui::LayerAnimationSequence* sequence) OVERRIDE {}
 
  private:
-  ui::LayerAnimationSequence* last_sequence_;
-
   DISALLOW_COPY_AND_ASSIGN(RotateHidingWindowAnimationObserver);
 };
 
@@ -482,8 +481,9 @@ void AddLayerAnimationsForRotate(aura::Window* window, bool show) {
   ui::LayerAnimationSequence* last_sequence =
       new ui::LayerAnimationSequence(transition.release());
   window->layer()->GetAnimator()->ScheduleAnimation(last_sequence);
+
   if (observer) {
-    observer->set_last_sequence(last_sequence);
+    observer->SetLastSequence(last_sequence);
     observer->DetachAndRecreateLayers();
   }
 }

ui/wm/core/window_animations_unittest.cc

@@ -288,4 +288,21 @@ TEST_F(WindowAnimationsTest, NotifyHideCompleted) {
   EXPECT_TRUE(animation_host.hide_completed());
 }
 
+// The rotation animation for hiding a window should not leak the animation
+// observer.
+TEST_F(WindowAnimationsTest, RotateHideNoLeak) {
+  ui::ScopedAnimationDurationScaleMode scale_mode(
+      ui::ScopedAnimationDurationScaleMode::FAST_DURATION);
+
+  scoped_ptr<aura::Window> window(aura::test::CreateTestWindowWithId(0, NULL));
+  ui::Layer* animating_layer = window->layer();
+  wm::SetWindowVisibilityAnimationType(window.get(),
+                                       WINDOW_VISIBILITY_ANIMATION_TYPE_ROTATE);
+
+  AnimateOnChildWindowVisibilityChanged(window.get(), true);
+  AnimateOnChildWindowVisibilityChanged(window.get(), false);
+
+  animating_layer->GetAnimator()->StopAnimating();
+}
+
 }  // namespace wm