Move have_wheel_event_handlers to WebLayerTreeView.

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 98ef993f1d0ccf947ad65fa5634cd5075c445775..1da5f9b71598039242ccfa8db283201dcd498e61 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -720,7 +720,7 @@ TEST_F(LayerTreeHostImplTest, ScrollBlocksOnWheelEventHandlers) {
 
   // With registered event handlers, wheel scrolls don't necessarily
   // have to go to the main thread.
-  root->SetHaveWheelEventHandlers(true);
+  host_impl_->active_tree()->set_have_wheel_event_handlers(true);
   InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
       BeginState(gfx::Point()).get(), InputHandler::WHEEL);
   EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
@@ -747,7 +747,7 @@ TEST_F(LayerTreeHostImplTest, ScrollBlocksOnWheelEventHandlers) {
 
   // And if the handlers go away, wheel scrolls can again be processed
   // on impl (despite the scroll-blocks-on mode).
-  root->SetHaveWheelEventHandlers(false);
+  host_impl_->active_tree()->set_have_wheel_event_handlers(false);
   status = host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL);
   EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
@@ -862,6 +862,8 @@ TEST_F(LayerTreeHostImplTest, ScrollBlocksOnLayerTopology) {
   LayerImpl* root = host_impl_->active_tree()->root_layer();
   DrawFrame();
 
+  host_impl_->active_tree()->set_have_wheel_event_handlers(true);
+
   // Create two child scrollable layers
   LayerImpl* child1 = 0;
   {
@@ -871,7 +873,6 @@ TEST_F(LayerTreeHostImplTest, ScrollBlocksOnLayerTopology) {
         7, gfx::Size(10, 10), scrollable_child_clip_1.get());
     child1 = scrollable_child_1.get();
     scrollable_child_1->SetPosition(gfx::PointF(5.f, 5.f));
-    scrollable_child_1->SetHaveWheelEventHandlers(true);
     scrollable_child_1->SetHaveScrollEventHandlers(true);
     scrollable_child_clip_1->AddChild(std::move(scrollable_child_1));
     root_child->AddChild(std::move(scrollable_child_clip_1));
@@ -886,7 +887,6 @@ TEST_F(LayerTreeHostImplTest, ScrollBlocksOnLayerTopology) {
         9, gfx::Size(10, 10), scrollable_child_clip_2.get());
     child2 = scrollable_child_2.get();
     scrollable_child_2->SetPosition(gfx::PointF(5.f, 20.f));
-    scrollable_child_2->SetHaveWheelEventHandlers(true);
     scrollable_child_2->SetHaveScrollEventHandlers(true);
     scrollable_child_clip_2->AddChild(std::move(scrollable_child_2));
     root_child->AddChild(std::move(scrollable_child_clip_2));