Fix crash when InkDropHostView::SetHasInkDrop() is called multiple times

ui/views/animation/ink_drop_host_view_unittest.cc

Index: ui/views/animation/ink_drop_host_view_unittest.cc
diff --git a/ui/views/animation/ink_drop_host_view_unittest.cc b/ui/views/animation/ink_drop_host_view_unittest.cc
index a9c8bccfbb399421a891820a3701cfe72ee5cba9..367239e74f801aa83d9f1c29180067f85b6813c6 100644
--- a/ui/views/animation/ink_drop_host_view_unittest.cc
+++ b/ui/views/animation/ink_drop_host_view_unittest.cc
@@ -57,5 +57,19 @@ TEST_F(InkDropHostViewTest, GetInkDropCenterBasedOnLastEventForLocatedEvent) {
   EXPECT_EQ(gfx::Point(5, 6), test_api_.GetInkDropCenterBasedOnLastEvent());
 }
 
+// Verifies that SetHasInkDrop() sets up gesture handling properly.
+TEST_F(InkDropHostViewTest, SetHasInkDropGestureHandler) {
+  EXPECT_FALSE(test_api_.HasGestureHandler());
+
+  test_api_.SetHasInkDrop(true);
+  EXPECT_TRUE(test_api_.HasGestureHandler());
+
+  test_api_.SetHasInkDrop(true);
+  EXPECT_TRUE(test_api_.HasGestureHandler());
+
+  test_api_.SetHasInkDrop(false);
+  EXPECT_FALSE(test_api_.HasGestureHandler());
+}
+
 }  // namespace test
 }  // namespace views