CC Animation: Move ElementId from animation to trees.

cc/animation/element_animations.h

 // 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.
 
 #ifndef CC_ANIMATION_ELEMENT_ANIMATIONS_H_
 #define CC_ANIMATION_ELEMENT_ANIMATIONS_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
-#include "cc/animation/element_id.h"
 #include "cc/animation/property_animation_state.h"
 #include "cc/animation/target_property.h"
 #include "cc/base/cc_export.h"
+#include "cc/trees/element_id.h"
 #include "ui/gfx/geometry/scroll_offset.h"
 #include "ui/gfx/transform.h"
 
 namespace gfx {
 class BoxF;
 }
 
 namespace cc {
 
 class AnimationDelegate;
@@ skipping 190 matching lines @@
   PropertyAnimationState pending_state_;
 
   bool needs_update_impl_client_state_;
 
   DISALLOW_COPY_AND_ASSIGN(ElementAnimations);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_ELEMENT_ANIMATIONS_H_