Move have_wheel_event_handlers to WebLayerTreeView.

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index 12ee4c0b7e76227d49a67e3120bf9cf1e5fb314b..f1a968aae4b86c34a68cf3c039835db3b84de2c0 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -500,11 +500,6 @@ class CC_EXPORT LayerImpl : public LayerAnimationValueObserver,
     return !!main_thread_scrolling_reasons_;
   }
 
-  void SetHaveWheelEventHandlers(bool have_wheel_event_handlers) {
-    have_wheel_event_handlers_ = have_wheel_event_handlers;
-  }
-  bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
-
   void SetHaveScrollEventHandlers(bool have_scroll_event_handlers) {
     have_scroll_event_handlers_ = have_scroll_event_handlers;
   }
@@ -775,7 +770,6 @@ class CC_EXPORT LayerImpl : public LayerAnimationValueObserver,
 
   gfx::Vector2dF offset_to_transform_parent_;
   uint32_t main_thread_scrolling_reasons_;
-  bool have_wheel_event_handlers_ : 1;
   bool have_scroll_event_handlers_ : 1;
 
   static_assert(SCROLL_BLOCKS_ON_MAX < (1 << 3), "ScrollBlocksOn too big");