Refactor GestureNavigation to eliminate code redundancy

content/browser/web_contents/web_contents_view_aura.cc

Index: content/browser/web_contents/web_contents_view_aura.cc
diff --git a/content/browser/web_contents/web_contents_view_aura.cc b/content/browser/web_contents/web_contents_view_aura.cc
index da9af68e420cdc09215582c10653ba5f9c4bb620..5ce1f9da8603205d510a0e592ad6b3e300db8c3e 100644
--- a/content/browser/web_contents/web_contents_view_aura.cc
+++ b/content/browser/web_contents/web_contents_view_aura.cc
@@ -22,7 +22,7 @@
 #include "content/browser/renderer_host/web_input_event_aura.h"
 #include "content/browser/web_contents/aura/gesture_nav_simple.h"
 #include "content/browser/web_contents/aura/overscroll_navigation_overlay.h"
-#include "content/browser/web_contents/aura/shadow_layer_delegate.h"
+#include "content/browser/web_contents/aura/overscroll_window_animation.h"
 #include "content/browser/web_contents/aura/window_slider.h"
 #include "content/browser/web_contents/touch_editable_impl_aura.h"
 #include "content/browser/web_contents/web_contents_impl.h"
@@ -60,7 +60,6 @@
 #include "ui/base/dragdrop/os_exchange_data.h"
 #include "ui/base/hit_test.h"
 #include "ui/compositor/layer.h"
-#include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/gfx/canvas.h"
@@ -88,18 +87,6 @@ bool IsScrollEndEffectEnabled() {
       switches::kScrollEndEffect) == "1";
 }
 
-bool ShouldNavigateForward(const NavigationController& controller,
-                           OverscrollMode mode) {
-  return mode == (base::i18n::IsRTL() ? OVERSCROLL_EAST : OVERSCROLL_WEST) &&
-         controller.CanGoForward();
-}
-
-bool ShouldNavigateBack(const NavigationController& controller,
-                        OverscrollMode mode) {
-  return mode == (base::i18n::IsRTL() ? OVERSCROLL_WEST : OVERSCROLL_EAST) &&
-         controller.CanGoBack();
-}
-
 RenderWidgetHostViewAura* ToRenderWidgetHostViewAura(
     RenderWidgetHostView* view) {
   if (!view || RenderViewHostFactory::has_factory())
@@ -113,65 +100,6 @@ RenderWidgetHostViewAura* ToRenderWidgetHostViewAura(
   return static_cast<RenderWidgetHostViewAura*>(view);
 }
 
-// The window delegate for the overscroll window. This redirects trackpad events
-// to the web-contents window. The delegate destroys itself when the window is
-// destroyed.
-class OverscrollWindowDelegate : public aura_extra::ImageWindowDelegate {
- public:
-  OverscrollWindowDelegate(WebContentsImpl* web_contents,
-                           OverscrollMode overscroll_mode)
-      : web_contents_(web_contents),
-        forward_events_(true) {
-    const NavigationControllerImpl& controller = web_contents->GetController();
-    const NavigationEntryImpl* entry = NULL;
-    if (ShouldNavigateForward(controller, overscroll_mode)) {
-      entry = controller.GetEntryAtOffset(1);
-    } else if (ShouldNavigateBack(controller, overscroll_mode)) {
-      entry = controller.GetEntryAtOffset(-1);
-    }
-
-    gfx::Image image;
-    if (entry && entry->screenshot().get()) {
-      std::vector<gfx::ImagePNGRep> image_reps;
-      image_reps.push_back(gfx::ImagePNGRep(entry->screenshot(), 1.0f));
-      image = gfx::Image(image_reps);
-    }
-    SetImage(image);
-  }
-
-  void stop_forwarding_events() { forward_events_ = false; }
-
- private:
-  ~OverscrollWindowDelegate() override {}
-
-  aura::Window* web_contents_window() {
-    return web_contents_->GetView()->GetContentNativeView();
-  }
-
-  // Overridden from ui::EventHandler.
-  void OnScrollEvent(ui::ScrollEvent* event) override {
-    if (forward_events_ && web_contents_window())
-      web_contents_window()->delegate()->OnScrollEvent(event);
-  }
-
-  void OnGestureEvent(ui::GestureEvent* event) override {
-    if (forward_events_ && web_contents_window())
-      web_contents_window()->delegate()->OnGestureEvent(event);
-  }
-
-  WebContentsImpl* web_contents_;
-
-  // The window is displayed both during the gesture, and after the gesture
-  // while the navigation is in progress. During the gesture, it is necessary to
-  // forward input events to the content page (e.g. when the overscroll window
-  // slides under the cursor and starts receiving scroll events). However, once
-  // the gesture is complete, and the window is being displayed as an overlay
-  // window during navigation, events should not be forwarded anymore.
-  bool forward_events_;
-
-  DISALLOW_COPY_AND_ASSIGN(OverscrollWindowDelegate);
-};
-
 // Listens to all mouse drag events during a drag and drop and sends them to
 // the renderer.
 class WebDragSourceAura : public NotificationObserver {
@@ -725,17 +653,17 @@ class WebContentsViewAura::WindowObserver
 ////////////////////////////////////////////////////////////////////////////////
 // WebContentsViewAura, public:
 
-WebContentsViewAura::WebContentsViewAura(
-    WebContentsImpl* web_contents,
-    WebContentsViewDelegate* delegate)
+WebContentsViewAura::WebContentsViewAura(WebContentsImpl* web_contents,
+                                         WebContentsViewDelegate* delegate)
     : web_contents_(web_contents),
       delegate_(delegate),
       current_drag_op_(blink::WebDragOperationNone),
       drag_dest_delegate_(NULL),
       current_rvh_for_drag_(NULL),
-      overscroll_change_brightness_(false),
       current_overscroll_gesture_(OVERSCROLL_NONE),
       completed_overscroll_gesture_(OVERSCROLL_NONE),
+      navigation_overlay_(nullptr),
+      overscroll_window_animation_(nullptr),
       touch_editable_(TouchEditableImplAura::Create()),
       is_or_was_visible_(false) {
 }
@@ -800,178 +728,36 @@ void WebContentsViewAura::InstallOverscrollControllerDelegate(
     return;
   }
   view->overscroll_controller()->set_delegate(this);
-  if (!navigation_overlay_)
-    navigation_overlay_.reset(new OverscrollNavigationOverlay(web_contents_));
-}
-
-void WebContentsViewAura::PrepareOverscrollWindow() {
-  // If there is an existing |overscroll_window_| which is in the middle of an
-  // animation, then destroying the window here causes the animation to be
-  // completed immediately, which triggers |OnImplicitAnimationsCompleted()|
-  // callback, and that tries to reset |overscroll_window_| again, causing a
-  // double-free. So use a temporary variable here.
-  if (overscroll_window_) {
-    base::AutoReset<OverscrollMode> reset_state(&current_overscroll_gesture_,
-                                                current_overscroll_gesture_);
-    scoped_ptr<aura::Window> reset_window(overscroll_window_.release());
+  LOG(ERROR) << "Installing OCD";
+  if (!overscroll_window_animation_) {

[mfomitchev, 2015/03/06 01:36:43]

Can we do the same thing for overscroll_window_animation_ that we are doing for
the overlay? E.g. if value == 0, it should be rest, etc.

[Nina, 2015/03/09 15:54:53]

Done.

+    overscroll_window_animation_.reset(
+        new OverscrollWindowAnimation());
   }
-
-  OverscrollWindowDelegate* overscroll_delegate = new OverscrollWindowDelegate(
-      web_contents_,
-      current_overscroll_gesture_);
-  overscroll_window_.reset(new aura::Window(overscroll_delegate));
-  overscroll_window_->SetType(ui::wm::WINDOW_TYPE_CONTROL);
-  overscroll_window_->SetTransparent(true);
-  overscroll_window_->Init(aura::WINDOW_LAYER_TEXTURED);
-  overscroll_window_->layer()->SetMasksToBounds(false);
-  overscroll_window_->SetName("OverscrollOverlay");
-
-  overscroll_change_brightness_ = overscroll_delegate->has_image();
-  window_->AddChild(overscroll_window_.get());
-
-  gfx::Rect bounds = gfx::Rect(window_->bounds().size());
-  if (ShouldNavigateForward(web_contents_->GetController(),
-                            current_overscroll_gesture_)) {
-    // The overlay will be sliding in from the right edge towards the left in
-    // non-RTL, or sliding in from the left edge towards the right in RTL.
-    // So position the overlay window accordingly.
-    bounds.Offset(base::i18n::IsRTL() ? -bounds.width() : bounds.width(), 0);
+  if (!navigation_overlay_) {
+    navigation_overlay_.reset(
+        new OverscrollNavigationOverlay(web_contents_,
+                                        overscroll_window_animation_.get(),
+                                        window_.get()));
+    overscroll_window_animation_->set_delegate(navigation_overlay_.get());
   }
-
-  aura::Window* animate_window = GetWindowToAnimateForOverscroll();
-  if (animate_window == overscroll_window_)
-    window_->StackChildAbove(overscroll_window_.get(), GetContentNativeView());
-  else
-    window_->StackChildBelow(overscroll_window_.get(), GetContentNativeView());
-
-  UpdateOverscrollWindowBrightness(0.f);
-
-  overscroll_window_->SetBounds(bounds);
-  overscroll_window_->Show();
-
-  overscroll_shadow_.reset(new ShadowLayerDelegate(animate_window->layer()));
+  LOG(ERROR) << "Installing overscroll window animation controller";
 }
 
 void WebContentsViewAura::PrepareContentWindowForOverscroll() {
-  StopObservingImplicitAnimations();
   aura::Window* content = GetContentNativeView();
   content->layer()->GetAnimator()->AbortAllAnimations();
   content->SetTransform(gfx::Transform());
   content->layer()->SetLayerBrightness(0.f);
 }
 
-void WebContentsViewAura::ResetOverscrollTransform() {
-  if (!web_contents_->GetRenderWidgetHostView())
-    return;
-  aura::Window* target = GetWindowToAnimateForOverscroll();
-  if (!target)
-    return;
-  {
-    ui::ScopedLayerAnimationSettings settings(target->layer()->GetAnimator());
-    settings.SetPreemptionStrategy(
-        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
-    settings.SetTweenType(gfx::Tween::EASE_OUT);
-    settings.AddObserver(this);
-    target->SetTransform(gfx::Transform());
-  }
-  {
-    ui::ScopedLayerAnimationSettings settings(target->layer()->GetAnimator());
-    settings.SetPreemptionStrategy(
-        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
-    settings.SetTweenType(gfx::Tween::EASE_OUT);
-    UpdateOverscrollWindowBrightness(0.f);
-  }
-}
-
 void WebContentsViewAura::CompleteOverscrollNavigation(OverscrollMode mode) {
   if (!web_contents_->GetRenderWidgetHostView())
     return;
 
-  // Animate out the current view first. Navigate to the requested history at
-  // the end of the animation.
-  if (current_overscroll_gesture_ == OVERSCROLL_NONE)
-    return;
-
   UMA_HISTOGRAM_ENUMERATION("Overscroll.Navigated",
                             current_overscroll_gesture_, OVERSCROLL_COUNT);
-  OverscrollWindowDelegate* delegate = static_cast<OverscrollWindowDelegate*>(
-      overscroll_window_->delegate());
-  delegate->stop_forwarding_events();
-
-  completed_overscroll_gesture_ = mode;
-  aura::Window* target = GetWindowToAnimateForOverscroll();
-  ui::ScopedLayerAnimationSettings settings(target->layer()->GetAnimator());
-  settings.SetPreemptionStrategy(
-      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
-  settings.SetTweenType(gfx::Tween::EASE_OUT);
-  settings.AddObserver(this);
-  gfx::Transform transform;
-  int content_width =
-      web_contents_->GetRenderWidgetHostView()->GetViewBounds().width();
-  float translate_x = static_cast<float>(mode == OVERSCROLL_WEST ?
-      -content_width : content_width);
-  transform.Translate(translate_x, 0);
-  target->SetTransform(transform);
-  UpdateOverscrollWindowBrightness(translate_x);
-}
-
-aura::Window* WebContentsViewAura::GetWindowToAnimateForOverscroll() {
-  if (current_overscroll_gesture_ == OVERSCROLL_NONE)
-    return NULL;
 
-  return ShouldNavigateForward(web_contents_->GetController(),
-                               current_overscroll_gesture_) ?
-      overscroll_window_.get() : GetContentNativeView();
-}
-
-gfx::Vector2dF WebContentsViewAura::GetTranslationForOverscroll(float delta_x,
-                                                                float delta_y) {
-  if (current_overscroll_gesture_ == OVERSCROLL_NORTH ||
-      current_overscroll_gesture_ == OVERSCROLL_SOUTH) {
-    return gfx::Vector2dF(0, delta_y);
-  }
-  // For horizontal overscroll, scroll freely if a navigation is possible. Do a
-  // resistive scroll otherwise.
-  const NavigationControllerImpl& controller = web_contents_->GetController();
-  const gfx::Rect& bounds = GetViewBounds();
-  const float bounds_width = static_cast<float>(bounds.width());
-  if (ShouldNavigateForward(controller, current_overscroll_gesture_))
-    return gfx::Vector2dF(std::max(-bounds_width, delta_x), 0);
-  else if (ShouldNavigateBack(controller, current_overscroll_gesture_))
-    return gfx::Vector2dF(std::min(bounds_width, delta_x), 0);
-  return gfx::Vector2dF();
-}
-
-void WebContentsViewAura::PrepareOverscrollNavigationOverlay() {
-  OverscrollWindowDelegate* delegate = static_cast<OverscrollWindowDelegate*>(
-      overscroll_window_->delegate());
-  overscroll_window_->SchedulePaintInRect(
-      gfx::Rect(overscroll_window_->bounds().size()));
-  overscroll_window_->SetBounds(gfx::Rect(window_->bounds().size()));
-  overscroll_window_->SetTransform(gfx::Transform());
-  navigation_overlay_->SetOverlayWindow(overscroll_window_.Pass(),
-                                        delegate);
-  navigation_overlay_->StartObserving();
-}
-
-void WebContentsViewAura::UpdateOverscrollWindowBrightness(float delta_x) {
-  if (!overscroll_change_brightness_)
-    return;
-
-  const float kBrightnessMin = -.1f;
-  const float kBrightnessMax = -.01f;
-
-  float ratio = fabs(delta_x) / GetViewBounds().width();
-  ratio = std::min(1.f, ratio);
-  if (base::i18n::IsRTL())
-    ratio = 1.f - ratio;
-  float brightness = current_overscroll_gesture_ == OVERSCROLL_WEST ?
-      kBrightnessMin + ratio * (kBrightnessMax - kBrightnessMin) :
-      kBrightnessMax - ratio * (kBrightnessMax - kBrightnessMin);
-  brightness = std::max(kBrightnessMin, brightness);
-  brightness = std::min(kBrightnessMax, brightness);
-  aura::Window* window = GetWindowToAnimateForOverscroll();
-  window->layer()->SetLayerBrightness(brightness);
+  overscroll_window_animation_->OnOverscrollComplete(mode);
 }
 
 void WebContentsViewAura::AttachTouchEditableToRenderView() {
@@ -1130,10 +916,6 @@ RenderWidgetHostViewBase* WebContentsViewAura::CreateViewForWidget(
   view->InitAsChild(NULL);
   GetNativeView()->AddChild(view->GetNativeView());
 
-  if (navigation_overlay_.get() && navigation_overlay_->has_window()) {
-    navigation_overlay_->StartObserving();
-  }
-
   RenderWidgetHostImpl* host_impl =
       RenderWidgetHostImpl::From(render_widget_host);
 
@@ -1166,8 +948,6 @@ void WebContentsViewAura::RenderViewCreated(RenderViewHost* host) {
 }
 
 void WebContentsViewAura::RenderViewSwappedIn(RenderViewHost* host) {
-  if (navigation_overlay_.get() && navigation_overlay_->has_window())
-    navigation_overlay_->StartObserving();
   AttachTouchEditableToRenderView();
 }
 
@@ -1182,8 +962,19 @@ void WebContentsViewAura::SetOverscrollControllerEnabled(bool enabled) {
 
   if (!enabled)
     navigation_overlay_.reset();

[mfomitchev, 2015/03/06 01:36:43]

reset OWA here as well

[Nina, 2015/03/09 15:54:53]

Done.

-  else if (!navigation_overlay_)
-    navigation_overlay_.reset(new OverscrollNavigationOverlay(web_contents_));
+  // TODO maybe we can delete this code, as it should be applied in
+  // InstallOverscrollControllerDelegate?
+  LOG(ERROR) << "Installing OCD";
+  if (!overscroll_window_animation_) {

[mfomitchev, 2015/03/06 01:36:43]

remove this if

[Nina, 2015/03/09 15:54:53]

Done.

+    overscroll_window_animation_.reset(
+        new OverscrollWindowAnimation());
+  } else if (!navigation_overlay_) {
+    navigation_overlay_.reset(

[mfomitchev, 2015/03/06 01:36:43]

Create OWA here as well

[Nina, 2015/03/09 15:54:53]

I rewrote this. OWA is now created on overscroll update if it did not exist.

[mfomitchev, 2015/03/10 19:25:59]

Hmm.. I don't really like that we are initializing everything in advance but we
delay initializing OWA until an overscroll happens. I think it would be better
if we were consistent.

[Nina, 2015/03/12 22:21:28]

Done.

+        new OverscrollNavigationOverlay(web_contents_,
+                                        overscroll_window_animation_.get(),
+                                        window_.get()));
+    overscroll_window_animation_->set_delegate(navigation_overlay_.get());
+  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1304,44 +1095,33 @@ bool WebContentsViewAura::OnOverscrollUpdate(float delta_x, float delta_y) {
   if (current_overscroll_gesture_ == OVERSCROLL_NONE)
     return false;
 
-  aura::Window* target = GetWindowToAnimateForOverscroll();
-  gfx::Vector2dF translate = GetTranslationForOverscroll(delta_x, delta_y);
-  gfx::Transform transform;
-
   if (current_overscroll_gesture_ == OVERSCROLL_NORTH ||
       current_overscroll_gesture_ == OVERSCROLL_SOUTH) {
-    OverscrollUpdateForWebContentsDelegate(translate.y());
-  } else {
-    // Only horizontal overscrolls participate in the navigation gesture.
-    transform.Translate(translate.x(), translate.y());
-    target->SetTransform(transform);
-    UpdateOverscrollWindowBrightness(delta_x);
+    OverscrollUpdateForWebContentsDelegate(delta_y);
+    return delta_y != 0;
   }
-
-  return !translate.IsZero();
+  // Only horizontal overscrolls participate in the navigation gesture.

[mfomitchev, 2015/03/06 01:36:43]

shouldn't this be inside else like it was before? If not - we should remove the
comment

[Nina, 2015/03/09 15:54:53]

We have a return on the other if, no need for an else.

+  if (!overscroll_window_animation_)

[mfomitchev, 2015/03/06 01:36:43]

Is this even possible? Previous flow ddidn't account for this case it seems

[Nina, 2015/03/09 15:54:53]

TBH I don't know as I didn't look much at the code for the Simple GestureNav.
Let's try removing it.

[mfomitchev, 2015/03/10 19:25:59]

I think overscroll events won't go to WCVA in the "simple gesture nav" case

[Nina, 2015/03/12 22:21:28]

Acknowledged.

+    return false;
+  return overscroll_window_animation_->OnOverscrollUpdate(delta_x, delta_y);
 }
 
 void WebContentsViewAura::OnOverscrollComplete(OverscrollMode mode) {
   UMA_HISTOGRAM_ENUMERATION("Overscroll.Completed", mode, OVERSCROLL_COUNT);
+  LOG(ERROR) << "OVERSCROLL COMPLETE";
   if (web_contents_->GetDelegate() &&
       IsScrollEndEffectEnabled() &&
       (mode == OVERSCROLL_NORTH || mode == OVERSCROLL_SOUTH)) {
     web_contents_->GetDelegate()->OverscrollComplete();
   }
-  NavigationControllerImpl& controller = web_contents_->GetController();
-  if (ShouldNavigateForward(controller, mode) ||
-      ShouldNavigateBack(controller, mode)) {
-    CompleteOverscrollNavigation(mode);
-    return;
-  }
-
-  ResetOverscrollTransform();
+  CompleteOverscrollNavigation(mode);
 }
 
 void WebContentsViewAura::OnOverscrollModeChange(OverscrollMode old_mode,
                                                  OverscrollMode new_mode) {
+  LOG(ERROR) << "Overscroll mode change";
   // Reset any in-progress overscroll animation first.
-  ResetOverscrollTransform();
+  // ResetOverscrollTransform();
 
   if (old_mode == OVERSCROLL_NORTH || old_mode == OVERSCROLL_SOUTH)
     OverscrollUpdateForWebContentsDelegate(0);
@@ -1349,58 +1129,22 @@ void WebContentsViewAura::OnOverscrollModeChange(OverscrollMode old_mode,
   if (new_mode != OVERSCROLL_NONE && touch_editable_)
     touch_editable_->OverscrollStarted();
 
+  overscroll_window_animation_->set_live_window(GetContentNativeView());

[mfomitchev, 2015/03/05 23:37:06]

Calling this every time the mode changes seems excessive

[Nina, 2015/03/09 15:54:53]

Yes, but it was necessary. I changed it so that we can use the web_contents
which is not ideal but at least now we don't crash if the ContentNativeView
changes.

   if (new_mode == OVERSCROLL_NONE ||
       !GetContentNativeView() ||
       ((new_mode == OVERSCROLL_EAST || new_mode == OVERSCROLL_WEST) &&
-       navigation_overlay_.get() && navigation_overlay_->has_window())) {
+       overscroll_window_animation_ &&
+       overscroll_window_animation_->is_active())) {
     current_overscroll_gesture_ = OVERSCROLL_NONE;
+    overscroll_window_animation_->OnOverscrollModeChange(old_mode,
+                                                         OVERSCROLL_NONE);
   } else {
-    aura::Window* target = GetWindowToAnimateForOverscroll();
-    if (target) {
-      StopObservingImplicitAnimations();
-      target->layer()->GetAnimator()->AbortAllAnimations();
-    }
-    // Cleanup state of the content window first, because that can reset the
-    // value of |current_overscroll_gesture_|.
-    PrepareContentWindowForOverscroll();
-
     current_overscroll_gesture_ = new_mode;
-    if (current_overscroll_gesture_ == OVERSCROLL_EAST ||
-        current_overscroll_gesture_ == OVERSCROLL_WEST)
-      PrepareOverscrollWindow();
-
-    UMA_HISTOGRAM_ENUMERATION("Overscroll.Started", new_mode, OVERSCROLL_COUNT);

[mfomitchev, 2015/03/06 01:36:43]

Looks like we lost this histogram

[Nina, 2015/03/09 15:54:53]

Brought back

-  }
-  completed_overscroll_gesture_ = OVERSCROLL_NONE;
-}
-
-////////////////////////////////////////////////////////////////////////////////
-// WebContentsViewAura, ui::ImplicitAnimationObserver implementation:
-
-void WebContentsViewAura::OnImplicitAnimationsCompleted() {
-  overscroll_shadow_.reset();
-
-  if (ShouldNavigateForward(web_contents_->GetController(),
-                            completed_overscroll_gesture_)) {
-    web_contents_->GetController().GoForward();
-    PrepareOverscrollNavigationOverlay();
-  } else if (ShouldNavigateBack(web_contents_->GetController(),
-                                completed_overscroll_gesture_)) {
-    web_contents_->GetController().GoBack();
-    PrepareOverscrollNavigationOverlay();
-  } else {
-    if (touch_editable_)
-      touch_editable_->OverscrollCompleted();
-  }
-
-  aura::Window* content = GetContentNativeView();
-  if (content) {
-    content->SetTransform(gfx::Transform());
-    content->layer()->SetLayerBrightness(0.f);
+    if (overscroll_window_animation_)
+      overscroll_window_animation_->OnOverscrollModeChange(old_mode, new_mode);
+    PrepareContentWindowForOverscroll();
   }
-  current_overscroll_gesture_ = OVERSCROLL_NONE;
   completed_overscroll_gesture_ = OVERSCROLL_NONE;
-  overscroll_window_.reset();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -1480,7 +1224,7 @@ void WebContentsViewAura::OnWindowDestroying(aura::Window* window) {
   // virtual functions to be called (e.g. OnImplicitAnimationsCompleted()). So
   // destroy the overscroll window here.
   navigation_overlay_.reset();
-  overscroll_window_.reset();
+  overscroll_window_animation_.reset();
 }
 
 void WebContentsViewAura::OnWindowDestroyed(aura::Window* window) {