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

ui/views/animation/ink_drop_host_view_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/animation/ink_drop_host_view.h"
 
 #include "base/macros.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
@@ skipping 39 matching lines @@
   host_view_.SetSize(gfx::Size(20, 20));
 
   ui::MouseEvent located_event(ui::ET_MOUSE_PRESSED, gfx::Point(5, 6),
                                gfx::Point(5, 6), ui::EventTimeForNow(),
                                ui::EF_LEFT_MOUSE_BUTTON, 0);
 
   test_api_.AnimateInkDrop(InkDropState::ACTION_PENDING, &located_event);
   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