Revert of Refactor GestureNavigation to eliminate code redundancy

content/browser/web_contents/aura/window_slider_unittest.cc

Index: content/browser/web_contents/aura/window_slider_unittest.cc
diff --git a/content/browser/web_contents/aura/window_slider_unittest.cc b/content/browser/web_contents/aura/window_slider_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a029dd8feb2fc2fbfdfa0a4cfe27cd050a7caadc
--- /dev/null
+++ b/content/browser/web_contents/aura/window_slider_unittest.cc
@@ -0,0 +1,639 @@
+// Copyright (c) 2013 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 "content/browser/web_contents/aura/window_slider.h"
+
+#include "base/bind.h"
+#include "base/time/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/aura/test/aura_test_base.h"
+#include "ui/aura/test/test_window_delegate.h"
+#include "ui/aura/window.h"
+#include "ui/base/hit_test.h"
+#include "ui/compositor/scoped_animation_duration_scale_mode.h"
+#include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/compositor/test/layer_animator_test_controller.h"
+#include "ui/events/event_processor.h"
+#include "ui/events/event_utils.h"
+#include "ui/events/test/event_generator.h"
+#include "ui/gfx/frame_time.h"
+
+namespace content {
+
+void DispatchEventDuringScrollCallback(ui::EventProcessor* dispatcher,
+                                       ui::Event* event,
+                                       ui::EventType type,
+                                       const gfx::Vector2dF& delta) {
+  if (type != ui::ET_GESTURE_SCROLL_UPDATE)
+    return;
+  ui::EventDispatchDetails details = dispatcher->OnEventFromSource(event);
+  CHECK(!details.dispatcher_destroyed);
+}
+
+void ChangeSliderOwnerDuringScrollCallback(scoped_ptr<aura::Window>* window,
+                                           WindowSlider* slider,
+                                           ui::EventType type,
+                                           const gfx::Vector2dF& delta) {
+  if (type != ui::ET_GESTURE_SCROLL_UPDATE)
+    return;
+  aura::Window* new_window = new aura::Window(NULL);
+  new_window->Init(ui::LAYER_TEXTURED);
+  new_window->Show();
+  slider->ChangeOwner(new_window);
+  (*window)->parent()->AddChild(new_window);
+  window->reset(new_window);
+}
+
+void ConfirmSlideDuringScrollCallback(WindowSlider* slider,
+                                      ui::EventType type,
+                                      const gfx::Vector2dF& delta) {
+  static float total_delta_x = 0;
+  if (type == ui::ET_GESTURE_SCROLL_BEGIN)
+    total_delta_x = 0;
+
+  if (type == ui::ET_GESTURE_SCROLL_UPDATE) {
+    total_delta_x += delta.x();
+    if (total_delta_x >= 70)
+      EXPECT_TRUE(slider->IsSlideInProgress());
+  } else {
+    EXPECT_FALSE(slider->IsSlideInProgress());
+  }
+}
+
+void ConfirmNoSlideDuringScrollCallback(WindowSlider* slider,
+                                        ui::EventType type,
+                                        const gfx::Vector2dF& delta) {
+  EXPECT_FALSE(slider->IsSlideInProgress());
+}
+
+// The window delegate does not receive any events.
+class NoEventWindowDelegate : public aura::test::TestWindowDelegate {
+ public:
+  NoEventWindowDelegate() {
+  }
+  ~NoEventWindowDelegate() override {}
+
+ private:
+  // Overridden from aura::WindowDelegate:
+  bool HasHitTestMask() const override { return true; }
+
+  DISALLOW_COPY_AND_ASSIGN(NoEventWindowDelegate);
+};
+
+class WindowSliderDelegateTest : public WindowSlider::Delegate {
+ public:
+  WindowSliderDelegateTest()
+      : can_create_layer_(true),
+        created_back_layer_(false),
+        created_front_layer_(false),
+        slide_completing_(false),
+        slide_completed_(false),
+        slide_aborted_(false),
+        slider_destroyed_(false) {
+  }
+  ~WindowSliderDelegateTest() override {
+    // Make sure slide_completed() gets called if slide_completing() was called.
+    CHECK(!slide_completing_ || slide_completed_);
+  }
+
+  void Reset() {
+    can_create_layer_ = true;
+    created_back_layer_ = false;
+    created_front_layer_ = false;
+    slide_completing_ = false;
+    slide_completed_ = false;
+    slide_aborted_ = false;
+    slider_destroyed_ = false;
+  }
+
+  void SetCanCreateLayer(bool can_create_layer) {
+    can_create_layer_ = can_create_layer;
+  }
+
+  bool created_back_layer() const { return created_back_layer_; }
+  bool created_front_layer() const { return created_front_layer_; }
+  bool slide_completing() const { return slide_completing_; }
+  bool slide_completed() const { return slide_completed_; }
+  bool slide_aborted() const { return slide_aborted_; }
+  bool slider_destroyed() const { return slider_destroyed_; }
+
+ protected:
+  ui::Layer* CreateLayerForTest() {
+    CHECK(can_create_layer_);
+    ui::Layer* layer = new ui::Layer(ui::LAYER_SOLID_COLOR);
+    layer->SetColor(SK_ColorRED);
+    return layer;
+  }
+
+  // Overridden from WindowSlider::Delegate:
+  ui::Layer* CreateBackLayer() override {
+    if (!can_create_layer_)
+      return NULL;
+    created_back_layer_ = true;
+    return CreateLayerForTest();
+  }
+
+  ui::Layer* CreateFrontLayer() override {
+    if (!can_create_layer_)
+      return NULL;
+    created_front_layer_ = true;
+    return CreateLayerForTest();
+  }
+
+  void OnWindowSlideCompleted(scoped_ptr<ui::Layer> layer) override {
+    slide_completed_ = true;
+  }
+
+  void OnWindowSlideCompleting() override { slide_completing_ = true; }
+
+  void OnWindowSlideAborted() override { slide_aborted_ = true; }
+
+  void OnWindowSliderDestroyed() override { slider_destroyed_ = true; }
+
+ private:
+  bool can_create_layer_;
+  bool created_back_layer_;
+  bool created_front_layer_;
+  bool slide_completing_;
+  bool slide_completed_;
+  bool slide_aborted_;
+  bool slider_destroyed_;
+
+  DISALLOW_COPY_AND_ASSIGN(WindowSliderDelegateTest);
+};
+
+// This delegate destroys the owner window when the slider is destroyed.
+class WindowSliderDeleteOwnerOnDestroy : public WindowSliderDelegateTest {
+ public:
+  explicit WindowSliderDeleteOwnerOnDestroy(aura::Window* owner)
+      : owner_(owner) {
+  }
+  ~WindowSliderDeleteOwnerOnDestroy() override {}
+
+ private:
+  // Overridden from WindowSlider::Delegate:
+  void OnWindowSliderDestroyed() override {
+    WindowSliderDelegateTest::OnWindowSliderDestroyed();
+    delete owner_;
+  }
+
+  aura::Window* owner_;
+  DISALLOW_COPY_AND_ASSIGN(WindowSliderDeleteOwnerOnDestroy);
+};
+
+// This delegate destroyes the owner window when a slide is completed.
+class WindowSliderDeleteOwnerOnComplete : public WindowSliderDelegateTest {
+ public:
+  explicit WindowSliderDeleteOwnerOnComplete(aura::Window* owner)
+      : owner_(owner) {
+  }
+  ~WindowSliderDeleteOwnerOnComplete() override {}
+
+ private:
+  // Overridden from WindowSlider::Delegate:
+  void OnWindowSlideCompleted(scoped_ptr<ui::Layer> layer) override {
+    WindowSliderDelegateTest::OnWindowSlideCompleted(layer.Pass());
+    delete owner_;
+  }
+
+  aura::Window* owner_;
+  DISALLOW_COPY_AND_ASSIGN(WindowSliderDeleteOwnerOnComplete);
+};
+
+typedef aura::test::AuraTestBase WindowSliderTest;
+
+TEST_F(WindowSliderTest, WindowSlideUsingGesture) {
+  scoped_ptr<aura::Window> window(CreateNormalWindow(0, root_window(), NULL));
+  window->SetBounds(gfx::Rect(0, 0, 400, 400));
+  WindowSliderDelegateTest slider_delegate;
+
+  ui::test::EventGenerator generator(root_window());
+
+  // Generate a horizontal overscroll.
+  WindowSlider* slider =
+      new WindowSlider(&slider_delegate, root_window(), window.get());
+  generator.GestureScrollSequenceWithCallback(
+      gfx::Point(10, 10),
+      gfx::Point(180, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10,
+      base::Bind(&ConfirmSlideDuringScrollCallback, slider));
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+  EXPECT_FALSE(slider->IsSlideInProgress());
+  slider_delegate.Reset();
+  window->SetTransform(gfx::Transform());
+
+  // Generate a horizontal overscroll in the reverse direction.
+  generator.GestureScrollSequenceWithCallback(
+      gfx::Point(180, 10),
+      gfx::Point(10, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10,
+      base::Bind(&ConfirmSlideDuringScrollCallback, slider));
+  EXPECT_TRUE(slider_delegate.created_front_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_back_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+  EXPECT_FALSE(slider->IsSlideInProgress());
+  slider_delegate.Reset();
+
+  // Generate a vertical overscroll.
+  generator.GestureScrollSequenceWithCallback(
+      gfx::Point(10, 10),
+      gfx::Point(10, 80),
+      base::TimeDelta::FromMilliseconds(10),
+      10,
+      base::Bind(&ConfirmNoSlideDuringScrollCallback, slider));
+  EXPECT_FALSE(slider_delegate.created_back_layer());
+  EXPECT_FALSE(slider_delegate.slide_completing());
+  EXPECT_FALSE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider->IsSlideInProgress());
+  slider_delegate.Reset();
+
+  // Generate a horizontal scroll that starts overscroll, but doesn't scroll
+  // enough to complete it.
+  generator.GestureScrollSequenceWithCallback(
+      gfx::Point(10, 10),
+      gfx::Point(80, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10,
+      base::Bind(&ConfirmSlideDuringScrollCallback, slider));
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_TRUE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_completing());
+  EXPECT_FALSE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+  EXPECT_FALSE(slider->IsSlideInProgress());
+  slider_delegate.Reset();
+
+  // Destroy the window. This should destroy the slider.
+  window.reset();
+  EXPECT_TRUE(slider_delegate.slider_destroyed());
+}
+
+// Tests that the window slide is interrupted when a different type of event
+// happens.
+TEST_F(WindowSliderTest, WindowSlideIsCancelledOnEvent) {
+  scoped_ptr<aura::Window> window(CreateNormalWindow(0, root_window(), NULL));
+  window->SetBounds(gfx::Rect(0, 0, 400, 400));
+  WindowSliderDelegateTest slider_delegate;
+
+  ui::Event* events[] = {
+      new ui::MouseEvent(ui::ET_MOUSE_MOVED, gfx::Point(55, 10),
+                         gfx::Point(55, 10), ui::EventTimeForNow(), 0, 0),
+      new ui::KeyEvent('a', ui::VKEY_A, ui::EF_NONE),
+      nullptr
+  };
+
+  new WindowSlider(&slider_delegate, root_window(), window.get());
+  for (int i = 0; events[i]; ++i) {
+    // Generate a horizontal overscroll.
+    ui::test::EventGenerator generator(root_window());
+    generator.GestureScrollSequenceWithCallback(
+        gfx::Point(10, 10),
+        gfx::Point(80, 10),
+        base::TimeDelta::FromMilliseconds(10),
+        1,
+        base::Bind(&DispatchEventDuringScrollCallback,
+                   root_window()->GetHost()->event_processor(),
+                   base::Owned(events[i])));
+    EXPECT_TRUE(slider_delegate.created_back_layer());
+    EXPECT_TRUE(slider_delegate.slide_aborted());
+    EXPECT_FALSE(slider_delegate.created_front_layer());
+    EXPECT_FALSE(slider_delegate.slide_completing());
+    EXPECT_FALSE(slider_delegate.slide_completed());
+    EXPECT_FALSE(slider_delegate.slider_destroyed());
+    slider_delegate.Reset();
+  }
+  window.reset();
+  EXPECT_TRUE(slider_delegate.slider_destroyed());
+}
+
+// Tests that the window slide can continue after it is interrupted by another
+// event if the user continues scrolling.
+TEST_F(WindowSliderTest, WindowSlideInterruptedThenContinues) {
+  scoped_ptr<aura::Window> window(CreateNormalWindow(0, root_window(), NULL));
+  window->SetBounds(gfx::Rect(0, 0, 400, 400));
+  WindowSliderDelegateTest slider_delegate;
+
+  ui::ScopedAnimationDurationScaleMode normal_duration_(
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
+  ui::LayerAnimator* animator = window->layer()->GetAnimator();
+  animator->set_disable_timer_for_test(true);
+  ui::LayerAnimatorTestController test_controller(animator);
+
+  WindowSlider* slider =
+      new WindowSlider(&slider_delegate, root_window(), window.get());
+
+  ui::MouseEvent interrupt_event(ui::ET_MOUSE_MOVED, gfx::Point(55, 10),
+                                 gfx::Point(55, 10), ui::EventTimeForNow(), 0,
+                                 0);
+
+  ui::test::EventGenerator generator(root_window());
+
+  // Start the scroll sequence. Scroll forward so that |window|'s layer is the
+  // one animating.
+  const int kTouchId = 5;
+  ui::TouchEvent press(ui::ET_TOUCH_PRESSED,
+                       gfx::Point(10, 10),
+                       kTouchId,
+                       ui::EventTimeForNow());
+  generator.Dispatch(&press);
+
+  // First scroll event of the sequence.
+  ui::TouchEvent move1(ui::ET_TOUCH_MOVED,
+                       gfx::Point(100, 10),
+                       kTouchId,
+                       ui::EventTimeForNow());
+  generator.Dispatch(&move1);
+  EXPECT_TRUE(slider->IsSlideInProgress());
+  EXPECT_FALSE(animator->is_animating());
+  // Dispatch the event after the first scroll and confirm it interrupts the
+  // scroll and starts  the "reset slide" animation.
+  generator.Dispatch(&interrupt_event);
+  EXPECT_TRUE(slider->IsSlideInProgress());
+  EXPECT_TRUE(animator->is_animating());
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  // slide_aborted() should be false because the 'reset slide' animation
+  // hasn't completed yet.
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_completing());
+  EXPECT_FALSE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+  slider_delegate.Reset();
+
+  // Second scroll event of the sequence.
+  ui::TouchEvent move2(ui::ET_TOUCH_MOVED,
+                       gfx::Point(200, 10),
+                       kTouchId,
+                       ui::EventTimeForNow());
+  generator.Dispatch(&move2);
+  // The second scroll should instantly cause the animation to complete.
+  EXPECT_FALSE(animator->is_animating());
+  EXPECT_FALSE(slider_delegate.created_back_layer());
+  // The ResetScroll() animation was completed, so now slide_aborted()
+  // should be true.
+  EXPECT_TRUE(slider_delegate.slide_aborted());
+
+  // Third scroll event of the sequence.
+  ui::TouchEvent move3(ui::ET_TOUCH_MOVED,
+                       gfx::Point(300, 10),
+                       kTouchId,
+                       ui::EventTimeForNow());
+  generator.Dispatch(&move3);
+  // The third scroll should re-start the sliding.
+  EXPECT_TRUE(slider->IsSlideInProgress());
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+
+  // Generate the release event, finishing the scroll sequence.
+  ui::TouchEvent release(ui::ET_TOUCH_RELEASED,
+                         gfx::Point(300, 10),
+                         kTouchId,
+                         ui::EventTimeForNow());
+  generator.Dispatch(&release);
+  // When the scroll gesture ends, the slide animation should start.
+  EXPECT_TRUE(slider->IsSlideInProgress());
+  EXPECT_TRUE(animator->is_animating());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+
+  // Progress the animator to complete the slide animation.
+  ui::ScopedLayerAnimationSettings settings(animator);
+  base::TimeDelta duration = settings.GetTransitionDuration();
+  test_controller.StartThreadedAnimationsIfNeeded();
+  animator->Step(gfx::FrameTime::Now() + duration);
+
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+
+  window.reset();
+  EXPECT_TRUE(slider_delegate.slider_destroyed());
+}
+
+// Tests that the slide works correctly when the owner of the window changes
+// during the duration of the slide.
+TEST_F(WindowSliderTest, OwnerWindowChangesDuringWindowSlide) {
+  scoped_ptr<aura::Window> parent(CreateNormalWindow(0, root_window(), NULL));
+
+  NoEventWindowDelegate window_delegate;
+  window_delegate.set_window_component(HTNOWHERE);
+  scoped_ptr<aura::Window> window(CreateNormalWindow(1, parent.get(),
+                                                     &window_delegate));
+
+  WindowSliderDelegateTest slider_delegate;
+  scoped_ptr<WindowSlider> slider(
+      new WindowSlider(&slider_delegate, parent.get(), window.get()));
+
+  // Generate a horizontal scroll, and change the owner in the middle of the
+  // scroll.
+  ui::test::EventGenerator generator(root_window());
+  aura::Window* old_window = window.get();
+  generator.GestureScrollSequenceWithCallback(
+      gfx::Point(10, 10),
+      gfx::Point(80, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      1,
+      base::Bind(&ChangeSliderOwnerDuringScrollCallback,
+                 base::Unretained(&window),
+                 slider.get()));
+  aura::Window* new_window = window.get();
+  EXPECT_NE(old_window, new_window);
+
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+}
+
+// If the delegate doesn't create the layer to show while sliding, WindowSlider
+// shouldn't start the slide or change delegate's state in any way in response
+// to user input.
+TEST_F(WindowSliderTest, NoSlideWhenLayerCantBeCreated) {
+  scoped_ptr<aura::Window> window(CreateNormalWindow(0, root_window(), NULL));
+  window->SetBounds(gfx::Rect(0, 0, 400, 400));
+  WindowSliderDelegateTest slider_delegate;
+  slider_delegate.SetCanCreateLayer(false);
+  WindowSlider* slider =
+      new WindowSlider(&slider_delegate, root_window(), window.get());
+
+  ui::test::EventGenerator generator(root_window());
+
+  // No slide in progress should be reported during scroll since the layer
+  // wasn't created.
+  generator.GestureScrollSequenceWithCallback(
+      gfx::Point(10, 10),
+      gfx::Point(180, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      1,
+      base::Bind(&ConfirmNoSlideDuringScrollCallback, slider));
+
+  EXPECT_FALSE(slider_delegate.created_back_layer());
+  EXPECT_FALSE(slider_delegate.slide_completing());
+  EXPECT_FALSE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+  window->SetTransform(gfx::Transform());
+
+  slider_delegate.SetCanCreateLayer(true);
+  generator.GestureScrollSequenceWithCallback(
+      gfx::Point(10, 10),
+      gfx::Point(180, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      10,
+      base::Bind(&ConfirmSlideDuringScrollCallback, slider));
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+
+  window.reset();
+  EXPECT_TRUE(slider_delegate.slider_destroyed());
+}
+
+// Tests that the owner window can be destroyed from |OnWindowSliderDestroyed()|
+// delegate callback without causing a crash.
+TEST_F(WindowSliderTest, OwnerIsDestroyedOnSliderDestroy) {
+  size_t child_windows = root_window()->children().size();
+  aura::Window* window = CreateNormalWindow(0, root_window(), NULL);
+  window->SetBounds(gfx::Rect(0, 0, 400, 400));
+  EXPECT_EQ(child_windows + 1, root_window()->children().size());
+
+  WindowSliderDeleteOwnerOnDestroy slider_delegate(window);
+  ui::test::EventGenerator generator(root_window());
+
+  // Generate a horizontal overscroll.
+  scoped_ptr<WindowSlider> slider(
+      new WindowSlider(&slider_delegate, root_window(), window));
+  generator.GestureScrollSequence(gfx::Point(10, 10),
+                                  gfx::Point(180, 10),
+                                  base::TimeDelta::FromMilliseconds(10),
+                                  10);
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+
+  slider.reset();
+  // Destroying the slider would have destroyed |window| too. So |window| should
+  // not need to be destroyed here.
+  EXPECT_EQ(child_windows, root_window()->children().size());
+}
+
+// Tests that the owner window can be destroyed from |OnWindowSlideComplete()|
+// delegate callback without causing a crash.
+TEST_F(WindowSliderTest, OwnerIsDestroyedOnSlideComplete) {
+  size_t child_windows = root_window()->children().size();
+  aura::Window* window = CreateNormalWindow(0, root_window(), NULL);
+  window->SetBounds(gfx::Rect(0, 0, 400, 400));
+  EXPECT_EQ(child_windows + 1, root_window()->children().size());
+
+  WindowSliderDeleteOwnerOnComplete slider_delegate(window);
+  ui::test::EventGenerator generator(root_window());
+
+  // Generate a horizontal overscroll.
+  new WindowSlider(&slider_delegate, root_window(), window);
+  generator.GestureScrollSequence(gfx::Point(10, 10),
+                                  gfx::Point(180, 10),
+                                  base::TimeDelta::FromMilliseconds(10),
+                                  10);
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_TRUE(slider_delegate.slider_destroyed());
+
+  // Destroying the slider would have destroyed |window| too. So |window| should
+  // not need to be destroyed here.
+  EXPECT_EQ(child_windows, root_window()->children().size());
+}
+
+// Test the scenario when two swipe gesture occur quickly one after another so
+// that the second swipe occurs while the transition animation triggered by the
+// first swipe is in progress.
+// The second swipe is supposed to instantly complete the animation caused by
+// the first swipe, ask the delegate to create a new layer, and animate it.
+TEST_F(WindowSliderTest, SwipeDuringSwipeAnimation) {
+  scoped_ptr<aura::Window> window(CreateNormalWindow(0, root_window(), NULL));
+  window->SetBounds(gfx::Rect(0, 0, 400, 400));
+  WindowSliderDelegateTest slider_delegate;
+  new WindowSlider(&slider_delegate, root_window(), window.get());
+
+  // This test uses explicit durations so needs a normal duration.
+  ui::ScopedAnimationDurationScaleMode normal_duration(
+      ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
+  ui::LayerAnimator* animator = window->layer()->GetAnimator();
+  animator->set_disable_timer_for_test(true);
+  ui::LayerAnimatorTestController test_controller(animator);
+
+  ui::test::EventGenerator generator(root_window());
+
+  // Swipe forward so that |window|'s layer is the one animating.
+  generator.GestureScrollSequence(
+      gfx::Point(10, 10),
+      gfx::Point(180, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      2);
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_FALSE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+  ui::ScopedLayerAnimationSettings settings(animator);
+  base::TimeDelta duration = settings.GetTransitionDuration();
+  test_controller.StartThreadedAnimationsIfNeeded();
+  base::TimeTicks start_time1 =  gfx::FrameTime::Now();
+
+  animator->Step(start_time1 + duration / 2);
+  EXPECT_FALSE(slider_delegate.slide_completed());
+  slider_delegate.Reset();
+  // Generate another horizontal swipe while the animation from the previous
+  // swipe is in progress.
+  generator.GestureScrollSequence(
+      gfx::Point(10, 10),
+      gfx::Point(180, 10),
+      base::TimeDelta::FromMilliseconds(10),
+      2);
+  // Performing the second swipe should instantly complete the slide started
+  // by the first swipe and create a new layer.
+  EXPECT_TRUE(slider_delegate.created_back_layer());
+  EXPECT_FALSE(slider_delegate.slide_aborted());
+  EXPECT_FALSE(slider_delegate.created_front_layer());
+  EXPECT_TRUE(slider_delegate.slide_completing());
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  EXPECT_FALSE(slider_delegate.slider_destroyed());
+  test_controller.StartThreadedAnimationsIfNeeded();
+  base::TimeTicks start_time2 =  gfx::FrameTime::Now();
+  slider_delegate.Reset();
+  animator->Step(start_time2 + duration);
+  // The animation for the second slide should now be completed.
+  EXPECT_TRUE(slider_delegate.slide_completed());
+  slider_delegate.Reset();
+
+  window.reset();
+  EXPECT_TRUE(slider_delegate.slider_destroyed());
+}
+
+}  // namespace content