Document some transform node animation fields.

cc/animation/animation_player.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/animation_player.h"
 
 #include <algorithm>
 
 #include "base/stl_util.h"
 #include "cc/animation/animation_delegate.h"
@@ skipping 989 matching lines @@
       return false;
     *max_scale = std::max(*max_scale, animation_scale);
   }
 
   return true;
 }
 
 bool AnimationPlayer::IsPotentiallyAnimatingProperty(
     TargetProperty::Type target_property,
     ElementListType list_type) const {
+  // TODO(wkorman): Consider refactoring this to share implementation
+  // with IsCurrentlyAnimatingProperty. The only difference is
+  // whether we consider InEffect(last_tick_time_) on each.
   for (size_t i = 0; i < animations_.size(); ++i) {
     if (!animations_[i]->is_finished() &&
         animations_[i]->target_property() == target_property) {
       if ((list_type == ElementListType::ACTIVE &&
            animations_[i]->affects_active_elements()) ||
           (list_type == ElementListType::PENDING &&
            animations_[i]->affects_pending_elements()))
         return true;
     }
   }
@@ skipping 185 matching lines @@
     if (current_impl)
       animations_[i]->PushPropertiesTo(current_impl);
   }
 
   animation_player_impl->scroll_offset_animation_was_interrupted_ =
       scroll_offset_animation_was_interrupted_;
   scroll_offset_animation_was_interrupted_ = false;
 }
 
 }  // namespace cc