Do not send mouse-move when target is destroyed due to synthesized mouse-exit in RootWindow

ui/aura/root_window_unittest.cc

Index: ui/aura/root_window_unittest.cc
diff --git a/ui/aura/root_window_unittest.cc b/ui/aura/root_window_unittest.cc
index c8fa601335af29bb6e6d54d973ac52e290c6deef..f10a23877791ee6581c949bd50d55b3e3446280a 100644
--- a/ui/aura/root_window_unittest.cc
+++ b/ui/aura/root_window_unittest.cc
@@ -1047,4 +1047,69 @@ TEST_F(RootWindowTest, GestureRepostEventOrder) {
             EventTypesToString(repost_event_recorder->events()));
 }
 
+class OnMouseExitDeletingEventFilter : public EventFilterRecorder {
+ public:
+  OnMouseExitDeletingEventFilter() : window_to_delete_(NULL) {}
+  virtual ~OnMouseExitDeletingEventFilter() {}
+
+  void set_window_to_delete(Window* window_to_delete) {
+    window_to_delete_ = window_to_delete;
+  }
+
+ private:
+  // Overridden from ui::EventHandler:
+  virtual void OnMouseEvent(ui::MouseEvent* event) OVERRIDE {
+    EventFilterRecorder::OnMouseEvent(event);
+    if (window_to_delete_) {
+      delete window_to_delete_;
+      window_to_delete_ = NULL;
+    }
+  }
+
+  Window* window_to_delete_;
+
+  DISALLOW_COPY_AND_ASSIGN(OnMouseExitDeletingEventFilter);
+};
+
+// Tests that RootWindow drops mouse-moved event that is supposed to be sent to
+// a child, but the child is destroyed because of the synthesized mouse-exit
+// event generated on the previous mouse_moved_handler_.
+TEST_F(RootWindowTest, DeleteWindowDuringMouseMovedDispatch) {
+  // Create window 1 and set its event filter. Window 1 will take ownership of
+  // the event filter.
+  scoped_ptr<Window> w1(CreateNormalWindow(1, root_window(), NULL));
+  OnMouseExitDeletingEventFilter* w1_filter =
+      new OnMouseExitDeletingEventFilter();
+  w1->SetEventFilter(w1_filter);
+  w1->SetBounds(gfx::Rect(20, 20, 60, 60));
+  EXPECT_EQ(NULL, root_window()->mouse_moved_handler());
+
+  test::EventGenerator generator(root_window(), w1.get());
+
+  // Move mouse over window 1 to set it as the |mouse_moved_handler_| for the
+  // root window.
+  generator.MoveMouseTo(51, 51);
+  EXPECT_EQ(w1.get(), root_window()->mouse_moved_handler());
+
+  // Create window 2 under the mouse cursor and stack it above window 1.
+  Window* w2 = CreateNormalWindow(2, root_window(), NULL);
+  w2->SetBounds(gfx::Rect(30, 30, 40, 40));
+  root_window()->StackChildAbove(w2, w1.get());
+
+  // Set window 2 as the window that is to be deleted when a mouse-exited event
+  // happens on window 1.
+  w1_filter->set_window_to_delete(w2);
+
+  // Move mosue over window 2. This should generate a mouse-exited event for
+  // window 1 resulting in deletion of window 2. The original mouse-moved event
+  // that was targeted to window 2 should be dropped since window 2 is
+  // destroyed. This test passes if no crash happens.
+  generator.MoveMouseTo(52, 52);
+  EXPECT_EQ(NULL, root_window()->mouse_moved_handler());
+
+  // Check events received by window 1.
+  EXPECT_EQ("MOUSE_ENTERED MOUSE_MOVED MOUSE_EXITED",
+            EventTypesToString(w1_filter->events()));
+}
+
 }  // namespace aura