Communicate whether passive event listeners exist to cc.

cc/trees/layer_tree_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_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 59 matching lines @@
       device_scale_factor_(1.f),
       painted_device_scale_factor_(1.f),
       elastic_overscroll_(elastic_overscroll),
       viewport_size_invalid_(false),
       needs_update_draw_properties_(true),
       needs_full_tree_sync_(true),
       next_activation_forces_redraw_(false),
       has_ever_been_drawn_(false),
       render_surface_layer_list_id_(0),
       have_scroll_event_handlers_(false),
-      have_wheel_event_handlers_(false),
+      event_listener_properties_(),
       top_controls_shrink_blink_size_(false),
       top_controls_height_(0),
       top_controls_shown_ratio_(top_controls_shown_ratio) {}
 
 LayerTreeImpl::~LayerTreeImpl() {
   BreakSwapPromises(IsActiveTree() ? SwapPromise::SWAP_FAILS
                                    : SwapPromise::ACTIVATION_FAILS);
 
   // Need to explicitly clear the tree prior to destroying this so that
   // the LayerTreeImpl pointer is still valid in the LayerImpl dtor.
@@ skipping 250 matching lines @@
       inner_viewport_scroll_layer_id_, outer_viewport_scroll_layer_id_);
 
   target_tree->RegisterSelection(selection_);
 
   // This should match the property synchronization in
   // LayerTreeHost::finishCommitOnImplThread().
   target_tree->set_source_frame_number(source_frame_number());
   target_tree->set_background_color(background_color());
   target_tree->set_has_transparent_background(has_transparent_background());
   target_tree->set_have_scroll_event_handlers(have_scroll_event_handlers());
-  target_tree->set_have_wheel_event_handlers(have_wheel_event_handlers());
+  target_tree->set_event_listener_properties(
+      EventListenerClass::kTouch,
+      event_listener_properties(EventListenerClass::kTouch));
+  target_tree->set_event_listener_properties(
+      EventListenerClass::kMouseWheel,
+      event_listener_properties(EventListenerClass::kMouseWheel));
 
   if (ViewportSizeInvalid())
     target_tree->SetViewportSizeInvalid();
   else
     target_tree->ResetViewportSizeInvalid();
 
   if (hud_layer())
     target_tree->set_hud_layer(static_cast<HeadsUpDisplayLayerImpl*>(
         LayerTreeHostCommon::FindLayerInSubtree(
             target_tree->root_layer(), hud_layer()->id())));
@@ skipping 1321 matching lines @@
       property_trees_.transform_tree, property_trees_.clip_tree,
       use_property_trees, &data_for_recursion);
   return data_for_recursion.closest_match;
 }
 
 struct HitTestVisibleScrollableOrTouchableFunctor {
   bool operator()(LayerImpl* layer) const {
     return layer->IsDrawnRenderSurfaceLayerListMember() ||
            ScrollsAnyDrawnRenderSurfaceLayerListMember(layer) ||
            !layer->touch_event_handler_region().IsEmpty() ||
-           layer->layer_tree_impl()->have_wheel_event_handlers();
+           layer->layer_tree_impl()->event_listener_properties(
+               EventListenerClass::kMouseWheel) !=
+               EventListenerProperties::kNone;
   }
 };
 
 LayerImpl* LayerTreeImpl::FindLayerThatIsHitByPoint(
     const gfx::PointF& screen_space_point) {
   if (!root_layer())
     return NULL;
   bool update_lcd_text = false;
   if (!UpdateDrawProperties(update_lcd_text))
     return NULL;
@@ skipping 339 matching lines @@
                                                    const gfx::BoxF& box,
                                                    gfx::BoxF* bounds) const {
   *bounds = gfx::BoxF();
   return layer_tree_host_impl_->animation_host()
              ? layer_tree_host_impl_->animation_host()
                    ->TransformAnimationBoundsForBox(layer->id(), box, bounds)
              : true;
 }
 
 }  // namespace cc