add has_element_in_any_list check in ElementAnimations::UpdateActivation

cc/animation/element_animations.cc

 // Copyright 2015 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 "cc/animation/element_animations.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 355 matching lines @@
     bool was_active = is_active_;
     is_active_ = false;
 
     for (auto& player : players_list_) {
       if (player.HasNonDeletedAnimation()) {
         is_active_ = true;
         break;
       }
     }
 
-    if (is_active_ && (!was_active || force)) {
+    if (is_active_ && (!was_active || force) && has_element_in_any_list()) {

[loyso (OOO), 2016/11/28 04:27:04]

Sohuldn't it be simple with a semantics similar to:
if (!has_element_in_any_list()) {
animation_host_->DidDeactivateElementAnimations(this); return; }
at the beginning of the function?

[junchao.han, 2016/11/28 07:27:45]

for 2 unit tests failed in patch set 3, UpdateActivation(ActivationType::FORCE)
is called. So the corner case only apply to (is_active_ && !was_active &&
has_element_in_any_list()). A new patch has been uploaded. PTAL

       animation_host_->DidActivateElementAnimations(this);
     } else if (!is_active_ && (was_active || force)) {
       // Resetting last_tick_time_ here ensures that calling ::UpdateState
       // before ::Animate doesn't start an animation.
       last_tick_time_ = base::TimeTicks();
       animation_host_->DidDeactivateElementAnimations(this);
     }
   }
 }
 
@@ skipping 179 matching lines @@
   if (animation_host()) {
     DCHECK(animation_host()->mutator_host_client());
     return animation_host()->mutator_host_client()->GetScrollOffsetForAnimation(
         element_id());
   }
 
   return gfx::ScrollOffset();
 }
 
 }  // namespace cc