Move have_wheel_event_handlers to WebLayerTreeView.

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 4e59132e01b8e7db64ea86bbd78a08b1e4eb861f..ffb93bd9aa08ea73e23945a87c09a28957090c1d 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -374,9 +374,6 @@ class CC_EXPORT LayerTreeImpl {
 
   LayerImpl* FindLayerThatIsHitByPoint(const gfx::PointF& screen_space_point);
 
-  LayerImpl* FindLayerWithWheelHandlerThatIsHitByPoint(
-      const gfx::PointF& screen_space_point);
-
   LayerImpl* FindLayerThatIsHitByPointInTouchHandlerRegion(
       const gfx::PointF& screen_space_point);
 
@@ -439,6 +436,11 @@ class CC_EXPORT LayerTreeImpl {
                                       const gfx::BoxF& box,
                                       gfx::BoxF* bounds) const;
 
+  bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
+  void set_have_wheel_event_handlers(bool have_event_handlers) {
+    have_wheel_event_handlers_ = have_event_handlers;
+  }
+
  protected:
   explicit LayerTreeImpl(
       LayerTreeHostImpl* layer_tree_host_impl,
@@ -526,10 +528,11 @@ class CC_EXPORT LayerTreeImpl {
 
   int render_surface_layer_list_id_;
 
+  bool have_wheel_event_handlers_;
+
   // Whether or not Blink's viewport size was shrunk by the height of the top
   // controls at the time of the last layout.
   bool top_controls_shrink_blink_size_;
-
   float top_controls_height_;
 
   // The amount that the top controls are shown from 0 (hidden) to 1 (fully