Re-enable Eager Gesture Recognition on Aura

ui/events/gesture_detection/gesture_event_data_packet.h

 // Copyright 2014 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 UI_EVENTS_GESTURE_DETECTION_GESTURE_EVENT_DATA_PACKET_H_
 #define UI_EVENTS_GESTURE_DETECTION_GESTURE_EVENT_DATA_PACKET_H_
 
 #include "base/containers/stack_container.h"
 #include "ui/events/gesture_detection/gesture_detection_export.h"
 #include "ui/events/gesture_detection/gesture_event_data.h"
@@ skipping 11 matching lines @@
     INVALID,               // The source of the gesture was invalid.
     TOUCH_SEQUENCE_START,  // The start of a new gesture sequence.
     TOUCH_SEQUENCE_END,    // The end of a gesture sequence.
     TOUCH_SEQUENCE_CANCEL, // The gesture sequence was cancelled.
     TOUCH_START,           // A touch down occured during a gesture sequence.
     TOUCH_MOVE,            // A touch move occured during a gesture sequence.
     TOUCH_END,             // A touch up occured during a gesture sequence.
     TOUCH_TIMEOUT,         // Timeout from an existing gesture sequence.
   };
 
+  enum class AckState : int {

[jdduke (slow), 2014/11/25 20:26:37]

Isn't the default type int? A shame to couple the ack here, but I guess the
packet has a very specific use anyhow.

[tdresser, 2014/11/26 15:17:18]

Perhaps I'm misinterpreting:
"Provide an explicit underlying type for enum classes and regular enums."
from 
https://chromium-cpp.appspot.com/

My interpretation was that you should always explicitly state the type.

Can you clarify what you mean by "Couple the ack"?

+    PENDING,
+    CONSUMED,
+    UNCONSUMED,
+  };
+
   GestureEventDataPacket();
   GestureEventDataPacket(const GestureEventDataPacket& other);
   ~GestureEventDataPacket();
   GestureEventDataPacket& operator=(const GestureEventDataPacket& other);
 
   // Factory methods for creating a packet from a particular event.
   static GestureEventDataPacket FromTouch(const ui::MotionEvent& touch);
   static GestureEventDataPacket FromTouchTimeout(
       const GestureEventData& gesture);
 
   void Push(const GestureEventData& gesture);
 
   const base::TimeTicks& timestamp() const { return timestamp_; }
   const GestureEventData& gesture(size_t i) const { return gestures_[i]; }
   size_t gesture_count() const { return gestures_->size(); }
   GestureSource gesture_source() const { return gesture_source_; }
   const gfx::PointF& touch_location() const { return touch_location_; }
   const gfx::PointF& raw_touch_location() const { return raw_touch_location_; }
 
+  // If we receive an ack for a packet before it reaches the head of the
+  // queue, we store the ack with the packet.
+  void ack(bool event_consumed) {

[jdduke (slow), 2014/11/25 20:26:37]

Hmm, I'd just as soon not make this inline.

[tdresser, 2014/11/26 15:17:18]

Done.

+    ack_state_ =
+        event_consumed ? AckState::CONSUMED : AckState::UNCONSUMED;
+  }
+  AckState ack_state() { return ack_state_; }
+
  private:
   GestureEventDataPacket(base::TimeTicks timestamp,
                          GestureSource source,
                          const gfx::PointF& touch_location,
                          const gfx::PointF& raw_touch_location);
 
   enum { kTypicalMaxGesturesPerTouch = 5 };
   base::TimeTicks timestamp_;
   base::StackVector<GestureEventData, kTypicalMaxGesturesPerTouch> gestures_;
   gfx::PointF touch_location_;
   gfx::PointF raw_touch_location_;
   GestureSource gesture_source_;
+  AckState ack_state_;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_GESTURE_DETECTION_GESTURE_EVENT_DATA_PACKET_H_