Move have_wheel_event_handlers to WebLayerTreeView.

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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 553 matching lines @@
   if ((scrolling_layer_impl == InnerViewportScrollLayer() &&
        test_layer_impl == OuterViewportScrollLayer()) ||
       (scrolling_layer_impl == OuterViewportScrollLayer() &&
        test_layer_impl == InnerViewportScrollLayer())) {
     return true;
   }
 
   return false;
 }
 
-bool LayerTreeHostImpl::HaveWheelEventHandlersAt(
-    const gfx::Point& viewport_point) {
-  gfx::PointF device_viewport_point = gfx::ScalePoint(
-      gfx::PointF(viewport_point), active_tree_->device_scale_factor());
-
-  LayerImpl* layer_impl =
-      active_tree_->FindLayerWithWheelHandlerThatIsHitByPoint(
-          device_viewport_point);
-
-  return layer_impl != NULL;
+bool LayerTreeHostImpl::HaveWheelEventHandlers() const {
+  return active_tree_->have_wheel_event_handlers();
 }
 
 static LayerImpl* NextLayerInScrollOrder(LayerImpl* layer) {
   if (layer->scroll_parent())
     return layer->scroll_parent();
 
   return layer->parent();
 }
 
 static ScrollBlocksOn EffectiveScrollBlocksOn(LayerImpl* layer) {
@@ skipping 3323 matching lines @@
   return task_runner_provider_->HasImplThread();
 }
 
 bool LayerTreeHostImpl::CommitToActiveTree() const {
   // In single threaded mode we skip the pending tree and commit directly to the
   // active tree.
   return !task_runner_provider_->HasImplThread();
 }
 
 }  // namespace cc