CC Animation: Move ElementId from animation to trees.

cc/trees/scroll_node.cc

 // Copyright 2016 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 "base/trace_event/trace_event_argument.h"
-#include "cc/animation/element_id.h"
 #include "cc/base/math_util.h"
 #include "cc/input/main_thread_scrolling_reason.h"
 #include "cc/proto/gfx_conversions.h"
+#include "cc/trees/element_id.h"
 #include "cc/trees/scroll_node.h"
 
 namespace cc {
 
 ScrollNode::ScrollNode()
     : id(-1),
       parent_id(-1),
       owner_id(-1),
       scrollable(false),
       main_thread_scrolling_reasons(
@@ skipping 43 matching lines @@
                              offset_to_transform_parent, value);
   value->SetBoolean("should_flatten", should_flatten);
   value->SetBoolean("user_scrollable_horizontal", user_scrollable_horizontal);
   value->SetBoolean("user_scrollable_vertical", user_scrollable_vertical);
 
   element_id.AddToTracedValue(value);
   value->SetInteger("transform_id", transform_id);
 }
 
 }  // namespace cc