cc: Disallow scroll offset animations when impl-scrolling isn't supported

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 "base/basictypes.h"
@@ skipping 240 matching lines @@
       micro_benchmark_controller_(this),
       need_to_update_visible_tiles_before_draw_(false),
 #if DCHECK_IS_ON
       did_lose_called_(false),
 #endif
       shared_bitmap_manager_(manager),
       id_(id),
       transfer_buffer_memory_limit_(0u) {
   DCHECK(proxy_->IsImplThread());
   DidVisibilityChange(this, visible_);
+  animation_registrar_->set_supports_scroll_animations(
+      proxy_->SupportsImplScrolling());
 
   SetDebugState(settings.initial_debug_state);
 
   if (settings.calculate_top_controls_position) {
     top_controls_manager_ =
         TopControlsManager::Create(this,
                                    settings.top_controls_height,
                                    settings.top_controls_show_threshold,
                                    settings.top_controls_hide_threshold);
   }
@@ skipping 2872 matching lines @@
 }
 
 void LayerTreeHostImpl::UnregisterPictureLayerImpl(PictureLayerImpl* layer) {
   std::vector<PictureLayerImpl*>::iterator it =
       std::find(picture_layers_.begin(), picture_layers_.end(), layer);
   DCHECK(it != picture_layers_.end());
   picture_layers_.erase(it);
 }
 
 }  // namespace cc