Notify Blink about start of gesture scroll through a queued event.

content/browser/renderer_host/input/touch_event_queue.h

Index: content/browser/renderer_host/input/touch_event_queue.h
diff --git a/content/browser/renderer_host/input/touch_event_queue.h b/content/browser/renderer_host/input/touch_event_queue.h
index 8a19586c618845acb6440c48b2dd0f2409e07e19..7c50e40b6e11fe0cbdd948799eb735b7ec58261d 100644
--- a/content/browser/renderer_host/input/touch_event_queue.h
+++ b/content/browser/renderer_host/input/touch_event_queue.h
@@ -70,6 +70,9 @@ class CONTENT_EXPORT TouchEventQueue {
   // the renderer (e.g. when there are no other queued touch event).
   void QueueEvent(const TouchEventWithLatencyInfo& event);
 
+  // Adds a TouchScrollStarted event to the front of the queue.
+  void PrependTouchScrollNotification();
+
   // Notifies the queue that a touch-event has been processed by the renderer.
   // At this point, if the ack is for async touchmove, remove the uncancelable
   // touchmove from the front of the queue and decide if it should dispatch the
@@ -109,8 +112,6 @@ class CONTENT_EXPORT TouchEventQueue {
   // Whether ack timeout behavior is supported and enabled for the current site.
   bool IsAckTimeoutEnabled() const;
 
-  bool IsForwardingTouches();
-
   bool empty() const WARN_UNUSED_RESULT {
     return touch_queue_.empty();
   }