[Notifications] Fix swipe to close for ARC notifications.

ui/message_center/views/slide_out_controller.cc

 // Copyright (c) 2012 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/message_center/views/slide_out_controller.h"
 
 #include "ui/compositor/layer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/transform.h"
 
@@ skipping 54 matching lines @@
   } else if (event->type() == ui::ET_GESTURE_SCROLL_END) {
     float scrolled_ratio = fabsf(gesture_amount_) / width;
     if (enabled_ && scrolled_ratio >= kScrollRatioForClosingNotification) {
       SlideOutAndClose(gesture_amount_);
       event->StopPropagation();
       return;
     }
     RestoreVisualState();
   }
 
+  delegate_->OnSlideChanged();

[Evan Stade, 2017/05/16 21:58:14]

Can the interested party (ArcCustomNotificationView) observe animations on the
slide out layer via LayerAnimationObserver?

[Eliot Courtney, 2017/05/17 04:48:25]

I tried this (by adding an override for OnLayerAnimationStarted), but it seems
to me like the animation is only for when the notification is slid out to close
(SlideOutAndClose), or restored back to its original position
(RestoreVisualState). ArcCustomNotificationView still needs to know about the
'animation' during the gesture.

   event->SetHandled();
 }
 
 void SlideOutController::RestoreVisualState() {
   ui::Layer* layer = delegate_->GetSlideOutLayer();
   // Restore the layer state.
   const int kSwipeRestoreDurationMS = 150;
   ui::ScopedLayerAnimationSettings settings(layer->GetAnimator());
   settings.SetTransitionDuration(
       base::TimeDelta::FromMilliseconds(kSwipeRestoreDurationMS));
   layer->SetTransform(gfx::Transform());
   layer->SetOpacity(1.f);
 }
 
 void SlideOutController::SlideOutAndClose(int direction) {
   ui::Layer* layer = delegate_->GetSlideOutLayer();
   const int kSwipeOutTotalDurationMS = 150;
   int swipe_out_duration = kSwipeOutTotalDurationMS * layer->opacity();
   ui::ScopedLayerAnimationSettings settings(layer->GetAnimator());
   settings.SetTransitionDuration(
       base::TimeDelta::FromMilliseconds(swipe_out_duration));
   settings.AddObserver(this);
 
   gfx::Transform transform;
   int width = layer->bounds().width();
   transform.Translate(direction < 0 ? -width : width, 0.0);
   layer->SetTransform(transform);
   layer->SetOpacity(0.f);
+  delegate_->OnSlideChanged();
 }
 
 void SlideOutController::OnImplicitAnimationsCompleted() {
   delegate_->OnSlideOut();
 }
 
 }  // namespace views