Remove the touch ack timeout handler out of the legacy touch event queue.

content/browser/renderer_host/input/legacy_touch_event_queue.h

Index: content/browser/renderer_host/input/legacy_touch_event_queue.h
diff --git a/content/browser/renderer_host/input/legacy_touch_event_queue.h b/content/browser/renderer_host/input/legacy_touch_event_queue.h
index 60f9c6b7f373a0b20baf212e7cacd2bf321f2d5f..8468cde1f02e9c3c98a5e56470bb69d4b03eea0d 100644
--- a/content/browser/renderer_host/input/legacy_touch_event_queue.h
+++ b/content/browser/renderer_host/input/legacy_touch_event_queue.h
@@ -24,6 +24,7 @@
 namespace content {
 
 class CoalescedWebTouchEvent;
+class TouchTimeoutHandler;
 
 // A queue for throttling and coalescing touch-events.
 class CONTENT_EXPORT LegacyTouchEventQueue : public TouchEventQueue {
@@ -95,8 +96,6 @@ class CONTENT_EXPORT LegacyTouchEventQueue : public TouchEventQueue {
   }
 
  private:
-  class TouchTimeoutHandler;
-  friend class TouchTimeoutHandler;
   friend class TouchEventQueueTest;
 
   bool HasPendingAsyncTouchMoveForTesting() const;
@@ -105,7 +104,7 @@ class CONTENT_EXPORT LegacyTouchEventQueue : public TouchEventQueue {
 
   // Empties the queue of touch events. This may result in any number of gesture
   // events being sent to the renderer.
-  void FlushQueue();
+  void FlushQueue() override;
 
   // Walks the queue, checking each event with |FilterBeforeForwarding()|.
   // If allowed, forwards the touch event and stops processing further events.
@@ -129,6 +128,10 @@ class CONTENT_EXPORT LegacyTouchEventQueue : public TouchEventQueue {
   void AckTouchEventToClient(InputEventAckState ack_result,
                              const ui::LatencyInfo* optional_latency_info);
 
+  // Dispatch a touch cancel event for the |event_to_cancel|.
+  void SendTouchCancelEventForTouchEvent(
+      const TouchEventWithLatencyInfo& event_to_cancel) override;
+
   // Dispatch |touch| to the client. Before dispatching, updates pointer
   // states in touchmove events for pointers that have not changed position.
   void SendTouchEventImmediately(TouchEventWithLatencyInfo* touch);
@@ -143,7 +146,7 @@ class CONTENT_EXPORT LegacyTouchEventQueue : public TouchEventQueue {
   PreFilterResult FilterBeforeForwarding(const blink::WebTouchEvent& event);
   void ForwardToRenderer(const TouchEventWithLatencyInfo& event);
   void UpdateTouchConsumerStates(const blink::WebTouchEvent& event,
-                                 InputEventAckState ack_result);
+                                 InputEventAckState ack_result) override;
   void FlushPendingAsyncTouchmove();
 
   // Handles touch event forwarding and ack'ed event dispatch.
@@ -151,10 +154,6 @@ class CONTENT_EXPORT LegacyTouchEventQueue : public TouchEventQueue {
 
   std::list<std::unique_ptr<CoalescedWebTouchEvent>> touch_queue_;
 
-  // Position of the first touch in the most recent sequence forwarded to the
-  // client.
-  gfx::PointF touch_sequence_start_position_;
-
   // Used to defer touch forwarding when ack dispatch triggers |QueueEvent()|.
   // True within the scope of |AckTouchEventToClient()|.
   bool dispatching_touch_ack_;