Notify OverscrollController of gesture events in plugins.

content/browser/renderer_host/render_widget_host_view_base.cc

Index: content/browser/renderer_host/render_widget_host_view_base.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_base.cc b/content/browser/renderer_host/render_widget_host_view_base.cc
index 527e5eac2ef065562cfc6fe029f5f0c56ea4bc4b..9a6befb68255b76586c661a4be042db11a74d0c4 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.cc
+++ b/content/browser/renderer_host/render_widget_host_view_base.cc
@@ -188,6 +188,12 @@ InputEventAckState RenderWidgetHostViewBase::FilterInputEvent(
   return INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
 }
 
+InputEventAckState RenderWidgetHostViewBase::FilterChildGestureEvent(
+    const blink::WebGestureEvent& gesture_event) {
+  // By default, do nothing with the child's gesture events.
+  return INPUT_EVENT_ACK_STATE_NOT_CONSUMED;
+}
+
 void RenderWidgetHostViewBase::WheelEventAck(
     const blink::WebMouseWheelEvent& event,
     InputEventAckState ack_result) {