Revert of Remove DCHECK_IMPLIES/CHECK_IMPLIES.

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 "cc/animation/animation_delegate.h"
 #include "cc/animation/animation_host.h"
 #include "cc/animation/animation_timeline.h"
 #include "cc/animation/element_animations.h"
@@ skipping 101 matching lines @@
     SetNeedsCommit();
   animations_.clear();
 }
 
 void AnimationPlayer::UnbindElementAnimations() {
   element_animations_ = nullptr;
   DCHECK(animations_.empty());
 }
 
 void AnimationPlayer::AddAnimation(scoped_ptr<Animation> animation) {
-  DCHECK(animation->target_property() != Animation::SCROLL_OFFSET ||
-         (animation_host_ && animation_host_->SupportsScrollAnimations()));
+  DCHECK_IMPLIES(
+      animation->target_property() == Animation::SCROLL_OFFSET,
+      animation_host_ && animation_host_->SupportsScrollAnimations());
 
   if (element_animations_) {
     element_animations_->layer_animation_controller()->AddAnimation(
         animation.Pass());
     SetNeedsCommit();
   } else {
     animations_.push_back(animation.Pass());
   }
 }
 
@@ skipping 46 matching lines @@
                                                        target_property, group);
 }
 
 void AnimationPlayer::SetNeedsCommit() {
   DCHECK(animation_host_);
   animation_host_->SetNeedsCommit();
   animation_host_->SetNeedsRebuildPropertyTrees();
 }
 
 }  // namespace cc