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 8c862b6e119e164212caf93455d5aba9d2f0f991..b039970ac45e02b604237226ab4f00288925a35d 100644
--- a/content/browser/renderer_host/render_widget_host_view_base.cc
+++ b/content/browser/renderer_host/render_widget_host_view_base.cc
@@ -187,6 +187,12 @@ 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::OnSetNeedsFlushInput() {
   if (flush_input_timer_.IsRunning())
     return;