compositor: Tick the UI animations from cc, instead of from timer callbacks.

ui/aura/window.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/aura/window.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 199 matching lines @@
       ignore_events_(false),
       // Don't notify newly added observers during notification. This causes
       // problems for code that adds an observer as part of an observer
       // notification (such as the workspace code).
       observers_(ObserverList<WindowObserver>::NOTIFY_EXISTING_ONLY) {
   set_target_handler(delegate_);
 }
 
 Window::~Window() {
   // |layer()| can be NULL during tests, or if this Window is layerless.
-  if (layer())
+  if (layer()) {
+    layer()->CompleteAllAnimations();

[ajuma, 2014/06/04 16:40:12]

I think we have cases where animations are expected to outlive the destruction
of the Window (the animation from http://crbug.com/341682 comes to mind as an
example). AIUI, in these cases the ownership of the animating layer is
transferred to an observer (like HidingWindowAnimationObserver) that destroys
the layer when the animation is completed.

[ajuma, 2014/06/04 17:13:12]

Sorry, that should be http://crbug.com/341862.

[sadrul, 2014/06/04 17:39:13]

For animating a window closing, we usually clone the layers first, and animate
them. The cloned layers becomes siblings to the original layers. So
destroying/stopping animations in the original layers do not affect the
animating cloned layers.

[ajuma, 2014/06/04 19:14:42]

Ah, things may have changed since the last time I was looking at the layer
cloning code (the cloning used to happen during OnWindowDestroying below, and
animations in progress before cloning were expected to continue). I'll defer to
sky@.

[sky, 2014/06/04 23:32:45]

I think you only want to do this if layer()->owner() == this. Otherwise someone
else owns the layer and presumably the animation should continue. Also, it would
be nice to have test coverage that animations are stopped.

[sadrul, 2014/06/05 01:03:36]

Done.
Done.

     layer()->SuppressPaint();
+  }
 
   // Let the delegate know we're in the processing of destroying.
   if (delegate_)
     delegate_->OnWindowDestroying(this);
   FOR_EACH_OBSERVER(WindowObserver, observers_, OnWindowDestroying(this));
 
   // TODO(beng): See comment in window_event_dispatcher.h. This shouldn't be
   //             necessary but unfortunately is right now due to ordering
   //             peculiarities. WED must be notified _after_ other observers
   //             are notified of pending teardown but before the hierarchy
@@ skipping 1196 matching lines @@
       return window;
     if (offset)
       *offset += window->bounds().OffsetFromOrigin();
   }
   if (offset)
     *offset = gfx::Vector2d();
   return NULL;
 }
 
 }  // namespace aura