Re-enable Eager Gesture Recognition on Aura

ui/events/gesture_detection/gesture_event_data_packet.h

Index: ui/events/gesture_detection/gesture_event_data_packet.h
diff --git a/ui/events/gesture_detection/gesture_event_data_packet.h b/ui/events/gesture_detection/gesture_event_data_packet.h
index 9b115de9ca77b29c2210b4933cd9a78acbb69198..0ae16ab04ff230fd78447fed20d7ad0abcadc25e 100644
--- a/ui/events/gesture_detection/gesture_event_data_packet.h
+++ b/ui/events/gesture_detection/gesture_event_data_packet.h
@@ -29,6 +29,12 @@ class GESTURE_DETECTION_EXPORT GestureEventDataPacket {
     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();
@@ -48,6 +54,14 @@ class GESTURE_DETECTION_EXPORT GestureEventDataPacket {
   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,
@@ -60,6 +74,7 @@ class GESTURE_DETECTION_EXPORT GestureEventDataPacket {
   gfx::PointF touch_location_;
   gfx::PointF raw_touch_location_;
   GestureSource gesture_source_;
+  AckState ack_state_;
 };
 
 }  // namespace ui