Remove all fling related stuff from the renderer assuming that browser side

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 7171580b86cc5eace6e844850c17792e15df7f21..1e4b3187e5b8c7c6868498cdb1de47d7a420033d 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -865,11 +865,6 @@ bool LayerTreeHostImpl::CalculateRenderPasses(FrameData* frame) {
   return draw_frame;
 }
 
-void LayerTreeHostImpl::MainThreadHasStoppedFlinging() {
-  if (input_handler_client_)
-    input_handler_client_->MainThreadHasStoppedFlinging();
-}
-
 void LayerTreeHostImpl::UpdateBackgroundAnimateTicking(
     bool should_background_tick) {
   DCHECK(proxy_->IsImplThread());
@@ -1442,8 +1437,7 @@ LayerImpl* LayerTreeHostImpl::CurrentlyScrollingLayer() const {
 }
 
 bool LayerTreeHostImpl::IsCurrentlyScrolling() const {
-  return CurrentlyScrollingLayer() ||
-         (RootScrollLayer() && RootScrollLayer()->IsExternalFlingActive());
+  return CurrentlyScrollingLayer();
 }
 
 // Content layers can be either directly scrollable or contained in an outer
@@ -2178,7 +2172,6 @@ bool LayerTreeHostImpl::ScrollBy(gfx::Point viewport_point,
     DidOverscrollParams params;
     params.accumulated_overscroll = accumulated_root_overscroll_;
     params.latest_overscroll_delta = unused_root_delta;
-    params.current_fling_velocity = current_fling_velocity_;
     input_handler_client_->DidOverscroll(params);
   }
 
@@ -2242,7 +2235,6 @@ void LayerTreeHostImpl::ClearCurrentlyScrollingLayer() {
   active_tree_->ClearCurrentlyScrollingLayer();
   did_lock_scrolling_layer_ = false;
   accumulated_root_overscroll_ = gfx::Vector2dF();
-  current_fling_velocity_ = gfx::Vector2dF();
 }
 
 void LayerTreeHostImpl::ScrollEnd() {
@@ -2252,27 +2244,6 @@ void LayerTreeHostImpl::ScrollEnd() {
   StartScrollbarAnimation();
 }
 
-InputHandler::ScrollStatus LayerTreeHostImpl::FlingScrollBegin() {
-  if (!active_tree_->CurrentlyScrollingLayer())
-    return ScrollIgnored;
-
-  if (settings_.ignore_root_layer_flings &&
-      active_tree_->CurrentlyScrollingLayer() ==
-          active_tree_->RootScrollLayer()) {
-    ClearCurrentlyScrollingLayer();
-    return ScrollIgnored;
-  }
-
-  if (!wheel_scrolling_)
-    should_bubble_scrolls_ = last_scroll_did_bubble_;
-
-  return ScrollStarted;
-}
-
-void LayerTreeHostImpl::NotifyCurrentFlingVelocity(gfx::Vector2dF velocity) {
-  current_fling_velocity_ = velocity;
-}
-
 float LayerTreeHostImpl::DeviceSpaceDistanceToLayer(
     gfx::PointF device_viewport_point,
     LayerImpl* layer_impl) {