Add suppresion of slop region touches in browser

content/browser/renderer_host/input/passthrough_touch_event_queue.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_INPUT_PASSTHROUGH_TOUCH_EVENT_QUEUE_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_PASSTHROUGH_TOUCH_EVENT_QUEUE_H_
 
 #include "content/browser/renderer_host/input/touch_event_queue.h"
 
 #include <set>
 
 namespace content {
 
 class TouchTimeoutHandler;
+class TouchMoveSlopSuppressor;
 
 // A queue that processes a touch-event and forwards it on to the
 // renderer process immediately. This class assumes that queueing will
 // happen inside the renderer process. This class will hold onto the pending
 // events so that it can re-order the acks so that they appear in a
 // logical order to the rest of the browser process. Due to the threaded
 // model of the renderer it is possible that an ack for a touchend can
 // be sent before the corresponding ack for the touchstart. This class
 // corrects that state.
 class CONTENT_EXPORT PassthroughTouchEventQueue : public TouchEventQueue {
@@ skipping 83 matching lines @@
   // Whether any pointer in the touch sequence may have having a consumer.
   bool maybe_has_handler_for_current_sequence_;
 
   // Whether to allow any remaining touches for the current sequence. Note that
   // this is a stricter condition than an empty |touch_consumer_states_|, as it
   // also prevents forwarding of touchstart events for new pointers in the
   // current sequence. This is only used when the event is synthetically
   // cancelled after a touch timeout.
   bool drop_remaining_touches_in_sequence_;
 
+  // Suppression of TouchMove's within a slop region when a sequence has not yet

[tdresser, 2017/04/13 18:13:35]

Suppression of -> Suppresses

[Navid Zolghadr, 2017/04/18 14:47:41]

Done.

+  // been preventDefaulted.
+  std::unique_ptr<TouchMoveSlopSuppressor> touchmove_slop_suppressor_;

[tdresser, 2017/04/13 18:13:35]

Why use a unique_ptr here, instead of just stack allocating?

[Navid Zolghadr, 2017/04/18 14:47:41]

If I don't use pointers here I need to put the full definition of that class in
the header file. I wanted to keep it private to this class and thus I defined
the class in the cpp file and kept a pointer here.

[tdresser, 2017/04/18 15:20:26]

Acknowledged.

+
   // Optional handler for timed-out touch event acks.
   std::unique_ptr<TouchTimeoutHandler> timeout_handler_;
 
   // Whether touch events should be sent as uncancelable or not.
   bool send_touch_events_async_;
 
   // Event is saved to compare pointer positions for new touchmove events.
   std::unique_ptr<blink::WebTouchEvent> last_sent_touchevent_;
 
   // Stores outstanding touches that have been sent to the renderer but have
   // not yet been ack'd by the renderer. The set is explicitly ordered based
   // on the unique touch event id.
   std::set<TouchEventWithLatencyInfoAndAckState> outstanding_touches_;
 
   DISALLOW_COPY_AND_ASSIGN(PassthroughTouchEventQueue);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_PASSTHROUGH_TOUCH_EVENT_QUEUE_H_