Fix unused variables errors in cc/.

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <set>
@@ skipping 224 matching lines @@
       micro_benchmark_controller_(this),
       shared_bitmap_manager_(shared_bitmap_manager),
       gpu_memory_buffer_manager_(gpu_memory_buffer_manager),
       task_graph_runner_(task_graph_runner),
       id_(id),
       requires_high_res_to_draw_(false),
       is_likely_to_require_a_draw_(false),
       frame_timing_tracker_(FrameTimingTracker::Create(this)) {
   if (settings.use_compositor_animation_timelines) {
     if (settings.accelerated_animation_enabled) {
-      animation_host_ = AnimationHost::Create(ThreadInstance::IMPL);
+      animation_host_ = AnimationHost::Create();
       animation_host_->SetMutatorHostClient(this);
       animation_host_->SetSupportsScrollAnimations(
           proxy_->SupportsImplScrolling());
     }
   } else {
     animation_registrar_ = AnimationRegistrar::Create();
     animation_registrar_->set_supports_scroll_animations(
         proxy_->SupportsImplScrolling());
   }
 
@@ skipping 3330 matching lines @@
     const gfx::ScrollOffset& scroll_offset) {
   if (tree_type == LayerTreeType::ACTIVE) {
     SetTreeLayerScrollOffsetMutated(layer_id, active_tree(), scroll_offset);
   } else {
     SetTreeLayerScrollOffsetMutated(layer_id, pending_tree(), scroll_offset);
     SetTreeLayerScrollOffsetMutated(layer_id, recycle_tree(), scroll_offset);
   }
 }
 
 }  // namespace cc