Fix for a crasher in the browser seen while dispatching mouse enter or mouse exit messages via the …

ui/views/widget/root_view_unittest.cc

Index: ui/views/widget/root_view_unittest.cc
diff --git a/ui/views/widget/root_view_unittest.cc b/ui/views/widget/root_view_unittest.cc
index fcefb7033020c19e0e19b8890838937b54e233f4..51f5892425c94f650f588d911bfa533a6883b2c1 100644
--- a/ui/views/widget/root_view_unittest.cc
+++ b/ui/views/widget/root_view_unittest.cc
@@ -4,6 +4,7 @@
 
 #include "ui/views/widget/root_view.h"
 
+#include "ui/events/event_utils.h"
 #include "ui/views/context_menu_controller.h"
 #include "ui/views/test/views_test_base.h"
 #include "ui/views/view_targeter.h"
@@ -337,5 +338,68 @@ TEST_F(RootViewTest, ContextMenuFromLongPressOnDisabledView) {
   EXPECT_EQ(0, controller.show_context_menu_calls());
 }
 
+// This view class provides functionality to delete itself in the context of
+// mouse exit event and helps test that we don't crash when we return from
+// the mouse exit handler.
+class DeleteViewOnMouseExit : public View {
+ public:
+  explicit DeleteViewOnMouseExit(bool* got_mouse_exit)
+      : got_mouse_exit_(got_mouse_exit) {
+  }
+
+  ~DeleteViewOnMouseExit() override {}
+
+  void OnMouseExited(const ui::MouseEvent& event) override {
+    *got_mouse_exit_ = true;
+    delete this;
+  }
+
+ private:
+  // Set to true in OnMouseExited().
+  bool* got_mouse_exit_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeleteViewOnMouseExit);
+};
+
+// Verifies deleting a View in OnMouseExited() doesn't crash.
+TEST_F(RootViewTest, DeleteViewOnMouseExitDispatch) {
+  Widget widget;
+  Widget::InitParams init_params =
+      CreateParams(Widget::InitParams::TYPE_POPUP);
+  init_params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+  widget.Init(init_params);
+  widget.SetBounds(gfx::Rect(10, 10, 500, 500));
+
+  View* content = new View;
+  widget.SetContentsView(content);
+
+  bool got_mouse_exit = false;
+  View* child = new DeleteViewOnMouseExit(&got_mouse_exit);
+  content->AddChildView(child);
+  child->SetBounds(10, 10, 500, 500);
+
+  child->SetFocusable(true);
+  child->RequestFocus();

[sadrul, 2015/03/18 22:30:00]

Don't need focus, right?

[ananta, 2015/03/19 00:02:55]

Done.

+
+  internal::RootView* root_view =
+      static_cast<internal::RootView*>(widget.GetRootView());
+
+  // Generate a mouse move event which ensures that the mouse_moved_handler_
+  // member is set in the RootView class.
+  ui::MouseEvent moved_event(ui::ET_MOUSE_MOVED, gfx::Point(15, 15),
+                             gfx::Point(100, 100), ui::EventTimeForNow(), 0,
+                             0);
+  root_view->OnMouseMoved(moved_event);

[sadrul, 2015/03/18 22:30:00]

EXPECT_FALSE here that !got_mouse_exit?

[ananta, 2015/03/19 00:02:55]

Done.

+
+  // Generate a mouse exit event which in turn will delete the child view which
+  // was the target of the mouse move event above. This should not crash when
+  // the mouse exit handler returns from the child.
+  ui::MouseEvent exit_event(ui::ET_MOUSE_EXITED, gfx::Point(), gfx::Point(),
+                            ui::EventTimeForNow(), 0, 0);
+  root_view->OnMouseExited(exit_event);
+
+  EXPECT_TRUE(got_mouse_exit);

[sadrul, 2015/03/18 22:30:00]

Also check that content->has_children() == false?

[ananta, 2015/03/19 00:02:55]

Done.

+}
+
 }  // namespace test
 }  // namespace views